Methods and systems for producing treated brines for desalination

ABSTRACT

Water treatment systems and associated methods are generally described. Certain embodiments of the water treatment systems and methods described herein may be used to treat water comprising one or more contaminants (e.g., oil, grease, suspended solids, scale-forming ions, volatile organic material) to remove at least a portion of the one or more contaminants. In some embodiments, at least a portion of the treated water may be used directly in certain applications (e.g., oil and/or gas extraction processes). In some embodiments, at least a portion of the treated water may undergo desalination to produce substantially pure water and/or concentrated brine.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application Ser. No. 62/115,120, filed Feb. 11, 2015,and entitled “Water Treatment Systems and Associated Methods,” which isincorporated herein by reference in its entirety for all purposes.

TECHNICAL FIELD

Systems for the treatment of water, and associated methods, aregenerally described.

BACKGROUND

Extraction of oil and gas from subterranean reservoirs may producecontaminated water as a byproduct (e.g., produced water). In some cases,it may be desirable to treat the contaminated water to remove one ormore contaminants. For example, treated water may be useful as adrilling fluid and/or a fracking fluid in oil and gas extractionoperations. In certain cases, it may be desirable to treat thecontaminated water to comply with government regulations.

In some cases, it may be desirable to feed the contaminated water to adesalination system to remove an amount of salt to produce fresh watersuitable for human consumption, irrigation, and/or industrial use.However, the presence of oils, suspended solids, scale-forming ions, andother contaminants in the contaminated water can complicate and impedethe operation of a desalination system. Accordingly, it may be desirableto pre-treat a contaminated water stream to remove at least a portion ofone or more contaminants prior to feeding the contaminated water streamto a desalination system.

Accordingly, improved systems for treating contaminated water areneeded.

SUMMARY

Water treatment systems and associated methods are generally described.The subject matter of the present invention involves, in some cases,interrelated products, alternative solutions to a particular problem,and/or a plurality of different uses of one or more systems and/orarticles.

Certain aspects relate to a method for treating water. In someembodiments, the method comprises supplying a saline water input streamhaving a first concentration of a scale-forming ion to an ion-removalapparatus; removing, within the ion-removal apparatus, at least aportion of the scale-forming ion from the saline water input stream toproduce a first ion-diminished stream having a second concentration ofthe scale-forming ion, wherein the second concentration is lower thanthe first concentration; collecting a product stream comprising at leasta portion of the first ion-diminished stream; removing, within theion-removal apparatus, at least a portion of the scale-forming ion fromthe saline water input stream to produce a second ion-diminished streamhaving a third concentration of the scale-forming ion, wherein the thirdconcentration is lower than the second concentration; and feeding thesecond ion-diminished stream to a desalination system to produce asubstantially pure water stream having a lower concentration of adissolved salt than the second ion-diminished stream and a concentratedbrine stream having a higher concentration of the dissolved salt thanthe second ion-diminished stream.

In some embodiments, the method for treating water comprises supplying asaline water input stream to a separation apparatus; removing, withinthe separation apparatus, at least a portion of at least one suspendedand/or emulsified immiscible phase from the saline water input stream toproduce an immiscible-phase-diminished stream containing less of theimmiscible phase relative to the saline water input stream; supplying atleast a portion of the immiscible-phase-diminished stream to anion-removal apparatus; removing, within the ion-removal apparatus, atleast a portion of at least one scale-forming ion from theimmiscible-phase-diminished stream to produce an ion-diminished streamcontaining less of the at least one scale-forming ion relative to theimmiscible-phase-diminished stream; and directing at least a portion ofthe ion-diminished stream to a storage tank.

Some aspects relate to a water treatment system. In some embodiments,the system comprises an ion-removal apparatus configured to remove atleast a portion of a scale-forming ion from a saline water input streamhaving a first concentration of the scale-forming ion to produce a firstion-diminished stream having a second concentration of the scale-formingion under a first set of operating conditions, wherein the secondconcentration is lower than the first concentration, and a secondion-diminished stream having a third concentration of the scale-formingion under a second set of operating conditions, wherein the thirdconcentration is lower than the second concentration, wherein theion-removal apparatus comprises an outlet configured to collect aproduct stream comprising at least a portion of the first ion-diminishedstream; and a desalination system fluidically connected to theion-removal apparatus, wherein the desalination system is configured toreceive the second ion-diminished stream and produce a substantiallypure water stream having a lower concentration of a dissolved salt thanthe second ion-diminished stream and a concentrated brine stream havinga higher concentration of the dissolved salt than the secondion-diminished stream.

According to some embodiments, a water treatment system comprises aclean brine system. In some embodiments, the clean brine systemcomprises a separation apparatus configured to remove at least a portionof at least one suspended and/or emulsified immiscible phase from anaqueous input stream received by the separation apparatus to produce animmiscible-phase-diminished stream containing less of the phase relativeto the aqueous input stream received by the separation apparatus; anion-removal apparatus fluidically connected to the separation apparatusand configured to remove at least a portion of at least onescale-forming ion from an aqueous input stream received by theion-removal apparatus to produce an ion-diminished stream containingless of the at least one scale-forming ion relative to the aqueous inputstream received by the ion-removal apparatus; a suspended solids removalapparatus fluidically connected to the separation apparatus andconfigured to remove at least a portion of suspended solids from anaqueous input stream received by the suspended solids removal apparatusto produce a suspended-solids-diminished stream containing lesssuspended solid material relative to the aqueous input stream receivedby the suspended solids removal apparatus; and a storage tankfluidically connected to at least one component of the clean brinesystem such that no intervening precipitation apparatus is fluidicallyconnected between the storage tank and the component.

Certain aspects relate to a method for forming concentrated brine. Insome embodiments, the method comprises supplying a saline water inputstream comprising an amount of suspended solids to a suspended solidsremoval apparatus; removing, within the suspended solids removalapparatus, at least a portion of the suspended solids from the salinewater input stream to produce a suspended-solids-diminished streamhaving a lower amount of suspended solids relative to the saline waterinput stream and a suspended-solids-enriched stream having a higheramount of suspended solids relative to the saline water input stream;supplying at least a portion of the suspended-solids-enriched stream toa filtration apparatus and removing at least a portion of liquid withinthe suspended-solids-enriched stream to form a filter cake; and addingan acid to the filter cake to form a brine solution comprising adissolved salt and having a density of at least about 9 pounds/gallon.

In some embodiments, the method for forming concentrated brine comprisessupplying a saline water input stream comprising an amount of suspendedsolids to a suspended solids removal apparatus; removing, within thesuspended solids removal apparatus, at least a portion of the suspendedsolids from the saline water input stream to produce asuspended-solids-diminished stream having a lower amount of suspendedsolids relative to the saline water input stream and asuspended-solids-enriched stream having a higher amount of suspendedsolids relative to the saline water input stream; supplying at least aportion of the suspended-solids-enriched stream to a filtrationapparatus and removing at least a portion of liquid within thesuspended-solids-enriched stream to form a substantially solid material;and adding an acid to the substantially solid material to dissolvesubstantially all of the substantially solid material to form a brinesolution comprising a dissolved salt.

Other advantages and novel features of the present invention will becomeapparent from the following detailed description of various non-limitingembodiments of the invention when considered in conjunction with theaccompanying figures. In cases where the present specification and adocument incorporated by reference include conflicting and/orinconsistent disclosure, the present specification shall control.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting embodiments of the present invention will be described byway of example with reference to the accompanying figures, which areschematic and are not intended to be drawn to scale. In the figures,each identical or nearly identical component illustrated is typicallyrepresented by a single numeral. For purposes of clarity, not everycomponent is labeled in every figure, nor is every component of eachembodiment of the invention shown where illustration is not necessary toallow those of ordinary skill in the art to understand the invention. Inthe figures:

FIG. 1 shows a schematic flow diagram of an exemplary water treatmentsystem comprising a clean brine system, a desalination system, and amixing apparatus, according to some embodiments;

FIG. 2A shows, according to some embodiments, a schematic flow diagramof an exemplary clean brine system comprising a separation apparatus, anion-removal apparatus, a suspended solids removal apparatus, a pHadjustment apparatus, a VOM removal apparatus, and a filtrationapparatus;

FIG. 2B shows, according to some embodiments, a schematic flow diagramof an exemplary clean brine system comprising a separation apparatus, anion-removal apparatus, a filtration apparatus, a pH adjustmentapparatus, and a VOM removal apparatus;

FIG. 3 shows a schematic flow diagram of an exemplary separationapparatus, according to some embodiments;

FIG. 4 shows, according to some embodiments, a schematic flow diagram ofan exemplary ion-removal apparatus;

FIG. 5 shows, according to some embodiments, a schematic flow diagram ofan exemplary pH adjustment apparatus;

FIG. 6 shows a schematic flow diagram of an exemplaryhumidification-dehumidification system, according to some embodiments;

FIG. 7 shows a schematic flow diagram of an exemplary water treatmentsystem, according to some embodiments;

FIG. 8 shows, according to some embodiments, a schematic flow diagram ofan exemplary water treatment system;

FIG. 9 shows a schematic flow diagram of an exemplary water treatmentsystem, according to some embodiments;

FIG. 10 shows, according to some embodiments, a schematic flow diagramof an exemplary water treatment system; and

FIG. 11 shows a schematic flow diagram of an exemplary water treatmentsystem, according to some embodiments.

DETAILED DESCRIPTION

Water treatment systems and associated methods are generally described.Certain embodiments of the water treatment systems and methods describedherein may be used to treat water comprising one or more contaminants(e.g., oil, grease, suspended solids, scale-forming ions, volatileorganic material) to remove at least a portion of the one or morecontaminants. In some embodiments, at least a portion of the treatedwater may be used directly in certain applications (e.g., oil and/or gasextraction processes). In some embodiments, at least a portion of thetreated water may undergo desalination to produce substantially purewater and/or concentrated brine. In some embodiments, at least a portionof the treated water may be used to produce concentrated brine withoutthe use of a desalination process.

It has been discovered within the context of this invention that asingle water treatment system may be capable of producing a variety ofproducts, including, but not limited to, clean brine, concentratedbrine, ultra-high-density brine, substantially pure water, mixed water(e.g., a water product comprising a combination of clean brine andsubstantially pure water), and/or solid salt. In some embodiments, thewater treatment system may comprise a clean brine system. According tocertain embodiments, the clean brine system may be used to treat asaline water input stream comprising one or more contaminants to produceclean brine (e.g., contaminant-diminished saline water). In someembodiments, the clean brine may be collected as a product stream. Incertain cases, the clean brine product stream may be directly used incertain applications (e.g., oil and/or gas extraction processes). Insome cases, the same clean brine system may be used to treat a salinewater input stream comprising one or more contaminants to produce cleanbrine suitable for desalination in a desalination system. According tosome embodiments, desalination of clean brine in the desalination systemmay produce substantially pure water and/or concentrated brine. In someembodiments, the substantially pure water may be collected as a productstream. In certain cases, the substantially pure water product streammay be used for human consumption, irrigation, industrial use, and/orother applications. In some embodiments, the concentrated brine may becollected as a product stream. In certain cases, the concentrated brineproduct stream may be directly used in certain applications (e.g., as akill fluid and/or drilling fluid in oil and/or gas extractionprocesses). In certain cases, at least a portion of the substantiallypure water may be mixed with at least a portion of the clean brine(e.g., clean brine for direct use) to produce a mixed water product,which may be collected as a product stream. In some embodiments, one ormore additional salts may be added to at least a portion of theconcentrated brine to produce an ultra-high-density brine. In certainembodiments, one or more salts may be precipitated from the concentratedbrine to produce solid salt. In some embodiments, the clean brine systemmay be used to produce concentrated brine in the absence ofdesalination. For example, in certain cases, a concentrated brine streammay be produced by adding an acid to a solid-containing stream producedby the clean brine system.

In some cases, it may be advantageous for a single water treatmentsystem to be capable of producing two or more product streams. Forexample, it may advantageously reduce costs (e.g., capital costs) tohave a single water treatment system instead of a plurality of watertreatment systems, each producing a particular type of product. Inaddition, a single water treatment system may have reduced maintenancerequirements, fewer components, and a smaller footprint than a pluralityof water treatment systems. Further, water treatment systems describedherein may advantageously have flexibility in producing different typesof products. This flexibility may be particularly desirable in the oiland gas industries, in which frequent changes to system designs may benecessary.

FIG. 1 is a schematic diagram of an exemplary water treatment system,according to some embodiments. As shown in FIG. 1, water treatmentsystem 100 comprises clean brine system 102, desalination system 110,and mixing apparatus 116, all of which are fluidically connected to oneanother. As described in further detail herein, clean brine system 102may comprise one or more units configured to remove one or morecontaminants from a saline water input stream. For example, clean brinesystem 102 may comprise a separation apparatus, an ion-removalapparatus, a suspended solids removal apparatus, a pH adjustmentapparatus, a volatile organic material (VOM) removal apparatus, and/or afiltration apparatus. Desalination system 110 may be any type ofdesalination system known in the art, and mixing apparatus 116 may beany type of mixing apparatus known in the art.

In operation, a saline water input stream 104 may enter clean brinesystem 102 from a source of saline water comprising one or morecontaminants. Non-limiting examples of the source of contaminated salinewater include an oil or gas well, a separator (e.g., a gravityseparator) configured to separate oil (e.g., produced oil) and water(e.g., produced water), and one or more tanks containing contaminatedsaline water. In some embodiments, clean brine system 102 may beconfigured to produce first clean brine stream 106 comprising a firstconcentration of one or more contaminants. First clean brine stream 106may, in some cases, be suitable for direct use in certain applications.For example, first clean brine stream 106 may be suitable for use in oiland/or gas extraction operations as a drilling fluid (e.g., a fluid thataids in drilling a wellbore) and/or a fracking fluid (e.g., a fluid thatis injected into a wellbore to assist in fracturing subterranean rockformations). In some embodiments, clean brine system 102 may beconfigured to produce second clean brine stream 108 comprising a secondconcentration of one or more contaminants. In certain cases, the secondconcentration may be lower than the first concentration, and secondclean brine stream 108 may be a suitable feed stream for a desalinationsystem. In certain cases, it may be desirable for second clean brinestream 108 to have a lower concentration of one or more contaminantsthan first clean brine stream 106. In some cases, desalination system110 may concentrate one or more salts and may comprise one or morecomponents (e.g., a heat exchanger) vulnerable to fouling (e.g., by saltformation). Accordingly, it may be preferred for a stream enteringdesalination system 110 to have lower concentrations of contaminants(e.g., scale-forming ions) to avoid forming scale within thedesalination system. In order to remove more contaminants for secondclean brine stream 108, chemical loading rates and/or the order ofchemical loading may be modified in clean brine system 102.

Clean brine system 102 may, in some embodiments, produce first cleanbrine stream 106 and second clean brine stream 108 in an alternatingmanner (e.g., during a first period of time clean brine system 102 mayproduce first clean brine stream 106, and during a second period of timeclean brine system 102 may produce second clean brine stream 108). Insome cases, producing one or more clean brine streams in an alternatingmanner may advantageously reduce costs (e.g., chemical costs). Forexample, such a system may require a lower amount of expensive chemicalsthan a system in which desalination-quality brine is continuouslyproduced.

In some embodiments, second clean brine stream 108 may enterdesalination system 110. In some cases, desalination system 110 mayproduce substantially pure water stream 112. In certain embodiments, afirst portion of substantially pure water stream 112 may optionally berecycled back to the desalination system and/or the clean brine system.In certain embodiments, a second portion of substantially pure waterstream 112 may optionally be discharged from water treatment system 100and collected as a product stream. In certain cases, a third portion ofsubstantially pure water stream 112 may optionally be mixed with atleast a portion of first clean brine stream 106 in mixing apparatus 116to produce mixed water stream 118. In addition to substantially purewater stream 112, desalination system 110 may produce concentrated brinestream 114, which may be collected as a product stream. In someembodiments, an amount of one or more salts may be added to at least aportion of concentrated brine stream 114 to produce anultra-high-density brine stream. In certain embodiments, one or moresalts may be precipitated from the concentrated brine stream to producea solid salt. According to certain embodiments, a precipitationapparatus (not shown in FIG. 1) may be fluidically connected todesalination system 110 to produce the solid salt.

It should be noted that water treatment system 100 may compriseadditional components. For example, water treatment system 100 mayfurther comprise one or more optional buffer tanks (not shown in FIG. 1)positioned between clean brine system 102 and desalination system 110.In some cases, the presence of one or more optional buffer tanks mayfacilitate continuous operation of desalination system 110. For example,the presence of a buffer tank may allow desalination system 110 tocontinue operating when clean brine system 102 is producing first cleanbrine stream 106 for direct use instead of second clean brine stream 108for desalination.

Water treatment systems and methods described herein may be used totreat water from a variety of sources. In some embodiments, a salinewater input stream comprises produced water (e.g., water that emergesfrom oil or gas wells along with the oil or gas). Due to the length oftime produced water has spent in the ground, and due to highsubterranean pressures and temperatures that may increase the solubilityof certain salts and/or minerals, produced water often comprisesrelatively high concentrations of dissolved salts and minerals. Forexample, some produced water streams may comprise a supersaturatedsolution of dissolved strontium sulfate (SrSO₄). In addition, producedwater may comprise a variety of other substances, including oil and/orgrease, organic compounds (e.g., benzene, toluene), scale-forming ions,and/or suspended solids. In some embodiments, at least a portion of thesaline water input stream comprises and/or is derived from seawater,ground water, brackish water, and/or wastewater (e.g., industrialwastewater). Non-limiting examples of wastewater include textile millwastewater, leather tannery wastewater, paper mill wastewater, coolingtower blowdown water, flue gas desulfurization wastewater, landfillleachate water, and/or the effluent of a chemical process (e.g., theeffluent of a desalination system, or another chemical process).

In certain systems described herein, a clean brine system is configuredto receive a stream of saline water comprising one or more contaminantsand remove at least a portion of the one or more contaminants to producea contaminant-diminished saline water stream (e.g., a clean brinestream). FIG. 2A is a schematic diagram of an exemplary clean brinesystem 102, according to some embodiments. As shown in FIG. 2A, cleanbrine system 102 comprises separation apparatus 202 configured to removeat least a portion of a suspended and/or emulsified immiscible phasefrom an aqueous stream, ion-removal apparatus 204 configured to removeat least a portion of at least one scale-forming ion from an aqueousstream, suspended solids removal apparatus 206 configured to remove atleast a portion of suspended solids from an aqueous stream, pHadjustment apparatus 208 configured to increase or decrease the pH of anaqueous stream, volatile organic material (VOM) removal apparatus 210configured to remove at least a portion of VOM from an aqueous stream,and filtration apparatus 212 configured to produce a solid product(e.g., filter cake).

In operation, saline water input stream 104 comprising a suspendedand/or emulsified immiscible phase, a scale-forming ion, suspendedsolids, and/or a volatile organic material is flowed to separationapparatus 202. Separation apparatus 202 removes at least a portion ofthe immiscible phase to produce immiscible-phase-diminished stream 214,which contains less of the immiscible phase than stream 104. In certainembodiments, separation apparatus 202 also producesimmiscible-phase-enriched stream 216, which contains more of theimmiscible phase than stream 104. Immiscible-phase-diminished stream 214is then flowed to ion-removal apparatus 204. Ion-removal apparatus 204removes at least a portion of at least one scale-forming ion to produceion-diminished stream 218, which contains less of at least onescale-forming ion than immiscible-phase-diminished stream 214. Incertain embodiments, ion-removal apparatus 204 also producesion-enriched stream 220, which contains more of at least onescale-forming ion than immiscible-phase-diminished stream 214.Ion-diminished stream 218 is then flowed to suspended solids removalapparatus 206. Suspended solids removal apparatus 206 removes at least aportion of suspended solids from ion-diminished stream 218 to producesuspended-solids-diminished stream 222, which contains less suspendedsolids than ion-diminished stream 218. Suspended solids removalapparatus 206 also produces suspended-solids-enriched stream 228, whichmay be flowed to filtration apparatus 212 to form solid stream 230 andfiltered liquid stream 232. Suspended-solids-diminished stream 222 maybe flowed to pH adjustment apparatus 208. pH adjustment apparatus 208may increase or decrease the pH of stream 222 to produce pH-adjustedstream 224. In some cases, chemicals 234 may be added in pH adjustmentapparatus 208 to increase or decrease the pH of stream 222. Stream 224may be flowed to VOM removal apparatus 210. VOM removal apparatus 210may remove at least a portion of VOM from stream 224 to produceVOM-diminished stream 108. VOM removal apparatus 210 may also produceVOM-enriched stream 226. VOM-diminished stream 108 may be dischargedfrom clean brine system 102 as clean brine stream 108. In some cases,clean brine stream 108 may be collected as a product stream for directuse (e.g., in oil or gas extraction). In some cases, clean brine stream108 may be flowed to a desalination system configured to remove at leasta portion of at least one dissolved salt from clean brine stream 108.

It should be noted that each of the components of clean brine system 102shown in FIG. 2A is optional, and a clean brine system may comprise anycombination of the components shown in FIG. 2A. For example, FIG. 2B isa schematic diagram of exemplary clean brine system 102 comprisingseparation apparatus 202 configured to remove at least a portion of asuspended and/or emulsified immiscible phase from an aqueous stream,ion-removal apparatus 204 configured to remove at least a portion of atleast one scale-forming ion from an aqueous stream, filtration apparatus212 configured to remove at least a portion of suspended solids from anaqueous stream and form a substantially solid material, pH adjustmentapparatus 208 configured to increase or decrease the pH of an aqueousstream, and volatile organic material (VOM) removal apparatus 210configured to remove at least a portion of VOM from an aqueous stream.

In operation, saline water input stream 104 comprising a suspendedand/or emulsified immiscible phase, a scale-forming ion, suspendedsolids, and/or a volatile organic material is flowed to separationapparatus 202. Separation apparatus 202 removes at least a portion ofthe immiscible phase to produce immiscible-phase-diminished stream 214,which contains less of the immiscible phase than stream 104. In certainembodiments, separation apparatus 202 also producesimmiscible-phase-enriched stream 216, which contains more of theimmiscible phase than stream 104. Immiscible-phase-diminished stream 214is then flowed to ion-removal apparatus 204. Ion-removal apparatus 204removes at least a portion of at least one scale-forming ion from stream214 to produce ion-diminished stream 218, which contains less of atleast one scale-forming ion than immiscible-phase-diminished stream 214.In certain embodiments, ion-removal apparatus 204 also producesion-enriched stream 220, which contains more of at least onescale-forming ion than immiscible-phase-diminished stream 214.Ion-diminished stream 218 is then flowed to filtration apparatus 212(e.g., a filter press, a vacuum filter). Filtration apparatus 212removes at least a portion of suspended solids from ion-diminishedstream 218 to form suspended-solids-diminished stream 232 (e.g., afiltered liquid stream), which contains less suspended solids thanion-diminished stream 218, and solid stream 230.Suspended-solids-diminished stream 232 may be flowed to pH adjustmentapparatus 208, which may increase or decrease the pH of stream 232 toproduce pH-adjusted stream 224. In some cases, chemicals 234 may beadded in pH adjustment apparatus 208 to increase or decrease the pH ofstream 232. Stream 224 may be flowed to VOM removal apparatus 210. VOMremoval apparatus 210 may remove at least a portion of VOM to produceVOM-diminished stream 108. VOM removal apparatus 210 may also produceVOM-enriched stream 226. VOM-diminished stream 108 may be dischargedfrom clean brine system 102 as clean brine stream 108.

A schematic diagram of an exemplary water treatment system comprisingexemplary clean brine system 102 (as shown in FIGS. 2A-B) and anexemplary desalination system is shown in FIG. 7, as described infurther detail below. Schematic diagrams of additional exemplary watertreatment systems are shown in FIGS. 8-10.

In some embodiments, the clean brine system comprises an optionalseparation apparatus configured to receive a saline water input streamand remove at least a portion of a suspended and/or emulsifiedimmiscible phase (e.g., a water-immiscible liquid phase) to produce animmiscible-phase-diminished saline water stream, which contains less ofthe immiscible phase than the saline water input stream. As used herein,a suspended and/or emulsified immiscible phase (e.g., a water-immisciblematerial) refers to a material that is not soluble in water to a levelof more than 10% by weight at the temperature and under the conditionsat which the separation apparatus operates. In some embodiments, thesuspended and/or emulsified immiscible phase comprises oil and/orgrease. As used herein, the term “oil” refers to a fluid that isgenerally more hydrophobic than water and is not miscible or soluble inwater, as is known in the art. Thus, the oil may be a hydrocarbon insome embodiments, but in other embodiments, the oil may comprise otherhydrophobic fluids.

In certain embodiments, the separation apparatus is configured to removea relatively large percentage of water-immiscible materials from thestream fed to the separation apparatus. For example, in someembodiments, the amount (in weight percentage, wt %) of at least onewater-immiscible material within the stream exiting the separationapparatus (e.g., stream 214 in FIG. 2) is at least about 50%, at leastabout 75%, at least about 90%, at least about 95%, or at least about 99%less than the amount of the at least one water-immiscible materialwithin the stream entering the separation apparatus (e.g., stream 104 inFIG. 2). To illustrate, if the stream exiting the separation apparatuscontains 5 wt % water-immiscible material, and the stream entering theseparation apparatus contains 50 wt % water-immiscible material, thenthe stream exiting the separation apparatus contains 90% lesswater-immiscible material than the stream entering the separationapparatus. In certain embodiments, the sum of the amounts of allwater-immiscible materials within the stream exiting the separationapparatus is at least about 50%, at least about 75%, at least about 90%,at least about 95%, or at least about 99% less than the sum of theamounts of all water-immiscible materials within the stream entering theseparation apparatus.

In some embodiments, the separation apparatus comprises one or moreseparators. FIG. 3 shows a schematic diagram of an exemplary separationapparatus. As shown in FIG. 3, separation apparatus 202 comprisesoptional strainer 302, primary separator 304, optional secondaryseparator 306, and optional water tank 308. In operation, saline waterinput stream 104 (e.g., corresponding to saline water input stream 104in FIG. 2) flows through optional strainer 302. Strainer 302 may beconfigured to prevent particles having a certain size from passingthrough strainer 302 to primary separator 304. Saline water stream 310,which is the portion of saline water input stream 104 that passesthrough strainer 302, may then flow to primary separator 304. In primaryseparator 304, water may be substantially separated from a suspendedand/or emulsified immiscible phase to produce firstimmiscible-phase-diminished stream 312, which contains lesswater-immiscible material than stream 310, and firstimmiscible-phase-enriched stream 314, which contains morewater-immiscible material than stream 310. Immiscible-phase-diminishedstream 312 may flow to water tank 308.

In some cases, immiscible-phase-enriched stream 314 may flow to optionalsecondary separator 306. In secondary separator 306, water-immisciblematerials may be separated from any water remaining in stream 314 toproduce second immiscible-phase-diminished stream 316 and secondimmiscible-phase-enriched stream 216. Second immiscible-phase-enrichedstream 216 may be discharged from separation apparatus 202, and secondimmiscible-phase-diminished stream 316 may be flowed to water tank 308.Immiscible-phase-diminished stream 214 formed by combining streams 312and 316 may then be discharged from separation apparatus 202.

In some embodiments, immiscible-phase-diminished stream 214 flows toanother unit of a clean brine system (e.g., an ion-removal apparatus, asuspended solids removal apparatus, a pH adjustment apparatus, avolatile organic material removal apparatus, a filtration apparatus). Insome embodiments, immiscible-material-diminished stream 214 isdischarged from a clean brine system as clean brine. In some cases, theclean brine may be made to flow to a desalination system. In some cases,the clean brine may be used directly in certain applications (e.g., oiland gas extraction operations). In certain embodiments, the clean brinemay be made to flow to one or more storage tanks.

The primary separator may be any type of separator known in the art. Insome cases, the primary separator may at least partially separate aportion of a suspended and/or emulsified immiscible phase from anaqueous stream via gravity, centrifugal force, adsorption, and/or usinga barrier.

According to certain embodiments, the primary separator is an inducedgas flotation (IGF) separator. An IGF separator generally refers to adevice configured to introduce bubbles of a gas into a volume of aliquid, where the gas bubbles adhere to particles (e.g., droplets ofwater-immiscible material, small solid particles) within the liquidvolume and cause the particles to float to the surface of the liquidvolume. In a particular embodiment, the gas is air, and the IGFseparator may be referred to as an induced air flotation (IAF)separator. Other examples of suitable gases include, but are not limitedto, carbon dioxide (CO₂), nitrogen (N₂), and/or natural gas.

In some embodiments, an IGF separator comprises a vessel capable ofholding a volume of liquid and a diffuser (e.g., a mechanical deviceconfigured to distribute a gas flow through a liquid volume). In certainembodiments, a low pressure zone (e.g., a zone having a pressure ofabout 100 kPa or less) that draws in ambient air may be formed in theIGF separator. For example, in certain cases, a low pressure zone may beformed by a rapidly rotating paddle inside a stationary diffuser or byrapid rotation of the diffuser itself. According to some embodiments,the diffuser is capable of introducing relatively small gas bubbles(e.g., gas bubbles having an average diameter of about 100 microns orless) into the liquid volume. In some cases, the relatively small gasbubbles adhere to particles (e.g., droplets of a water-immisciblematerial, suspended solid particles) within the liquid volume and causethe particles to float to the surface of the liquid volume. In someembodiments, a portion of the liquid volume below the surface (e.g., aportion of the liquid volume that is substantially free of gas bubblesand associated particles) may exit the IGF separator (e.g., through anunderflow weir) as an immiscible-phase-diminished stream. In someembodiments, a portion of the material floating on the surface of theliquid volume may exit the IGF separator (e.g., over an underflow weir)as an immiscible-phase-enriched stream.

In some embodiments, use of an IGF separator may be associated withcertain advantages. For example, in addition to removing at least aportion of a suspended and/or emulsified immiscible phase, an IGFseparator may be capable of removing at least a portion of one or morevolatile organic materials (VOMs) from a saline water input stream. Asused herein, the term “volatile organic material” or “VOM” is used todescribe organic materials that at least partially evaporate at 25° C.and 1 atmosphere. In some embodiments, the IGF separator is capable ofremoving at least a portion of one or more dissolved gases from a salinewater input stream. A non-limiting example of a dissolved gas that maybe removed from a saline water input stream by an IGF separator ishydrogen sulfide (H₂S). Without wishing to be bound by a particulartheory, at least a portion of one or more dissolved gases may be drawnout of solution by a low pressure zone formed by a diffuser of the IGFseparator and/or may diffuse into the gas bubbles. In certainembodiments, gas exiting the IGF separator may be vented to reduce thepossibility of buildup of one or more flammable gases.

Although the primary separator has been described as being an IGFseparator, it should be noted that the primary separator may be anyother type of separator known in the art. For example, the primaryseparator may comprise a hydrocyclone (e.g., a de-oiling hydrocyclone),a corrugated plate interceptor, an adsorption media filter, a coalescingmedia filter, a membrane filter, a gravity separator (e.g., an AmericanPetroleum Institute (API) separator), a dissolved gas flotation (DGF)separator, and/or a skimmer.

In some embodiments, an aqueous stream flowing through the primaryseparator has a relatively short residence time in the primaryseparator. In some embodiments, the residence time of an aqueous streamflowing through the primary separator is about 30 minutes or less, about20 minutes or less, about 10 minutes or less, about 8 minutes or less,about 6 minutes or less, about 4 minutes or less, about 2 minutes orless, or about 1 minute or less. In some embodiments, the residence timeof the aqueous input stream in the primary separator is in the range ofabout 1 minute to about 30 minutes, about 1 minute to about 20 minutes,about 1 minute to about 10 minutes, about 1 minute to about 8 minutes,about 1 minute to about 6 minutes, about 1 minute to about 4 minutes, orabout 1 minute to about 2 minutes.

Those of ordinary skill in the art are capable of determining theresidence time of a volume of fluid in a vessel. For a batch (i.e.,non-flow) apparatus, the residence time corresponds to the amount oftime the fluid spends in the vessel. For a flow-based apparatus, theresidence time is determined by dividing the volume of the vessel by thevolumetric flow rate of the fluid through the vessel.

In some embodiments, the separation apparatus further comprises asecondary separator positioned downstream of a primary separator. Insome cases, the secondary separator is configured to remove at least aportion of a suspended and/or emulsified immiscible phase from animmiscible-phase-enriched stream received from the primary separator.

The secondary separator may be any type of separator known in the art.In some cases, the secondary separator may at least partially separate aportion of a suspended and/or emulsified immiscible phase from anaqueous stream via gravity, centrifugal force, adsorption, and/or usinga barrier.

According to certain embodiments, the secondary separator comprises adissolved gas flotation (DGF) separator. A dissolved gas flotationapparatus generally refers to a device configured to dissolve a gas intoa liquid volume. In some cases, the gas may be dissolved in the liquidvolume through the generation of very high pressure zones. In certainembodiments, the dissolved gas may precipitate as small gas bubbles(e.g., having an average diameter of about 10 microns or less). In someembodiments, the small gas bubbles may nucleate on particles (e.g.,droplets of water-immiscible material, suspended solid particles), andthe bubbles and associated particles may float to the surface of theliquid volume. In certain embodiments, the gas is air, and the DGFseparator may be referred to as a dissolved air flotation (DAF)separator. In certain cases, the density of air bubbles in a liquidvolume may be relatively low. In some cases, the relatively low densityof air bubbles may advantageously increase the rate of buoyancy-drivenseparation between water and water-immiscible materials.

In certain embodiments, the secondary separator comprises a gravityseparator. In some cases, the gravity separator comprises a settlingtank, and water and water-immiscible material in animmiscible-phase-enriched stream received by the gravity separator maybe at least partially physically separated within the settling tank. Incertain cases, water present in the immiscible-phase-enriched streamreceived by the gravity separator may settle at the bottom of a settlingtank, while water-immiscible material may float to the top of thesettling tank. In certain embodiments, this separation may be at leastpartially attributed to differences in the specific gravity of water andwater-immiscible material. In certain cases, at least a portion of thewater-immiscible material (e.g., oil) may be recovered from the settlingtank. The water-immiscible material may subsequently be stored and/ortransported off-site.

In some embodiments, water recovered from the immiscible-phase-enrichedstream may be combined with the immiscible-phase-diminished streamproduced by the primary separator. In certain cases, theimmiscible-phase-diminished streams may be made to flow into one or morebuffer tanks and/or storage tanks. In certain cases, theimmiscible-phase-diminished streams may be made to flow to othercomponents of a clean brine system (e.g., ion-removal apparatus,suspended solids removal apparatus, pH adjustment apparatus, volatileorganic material removal apparatus, filtration apparatus). In somecases, the immiscible-material-diminished streams may be discharged fromthe clean brine system as clean brine.

In some embodiments, an aqueous stream flowing through the secondaryseparator has a relatively long residence time in the secondaryseparating apparatus. In some embodiments, the residence time of anaqueous stream in the secondary separator is at least about 5 minutes,at least about 10 minutes, at least about 15 minutes, at least about 20minutes, at least about 25 minutes, at least about 30 minutes, at leastabout 40 minutes, at least about 50 minutes, or at least about 60minutes. In some embodiments, the residence time of an aqueous stream inthe secondary separator is in the range of about 5 minutes to about 30minutes, about 10 minutes to about 30 minutes, about 15 minutes to about30 minutes, about 20 minutes to about 30 minutes, or about 25 minutes toabout 30 minutes.

In some embodiments, the residence time of an aqueous stream flowingthrough the secondary separator may be longer than the residence time ofan aqueous stream flowing through the primary separator. In some cases,the residence time of an aqueous stream flowing through the secondaryseparator may be larger than the residence time of an aqueous streamflowing through the primary separator by at least about 5 minutes, atleast about 10 minutes, at least about 15 minutes, at least about 20minutes, at least about 25 minutes, or at least about 30 minutes. Incertain embodiments, it may be advantageous for the secondary separatorto have a longer residence time than the primary separating apparatus.For example, a longer residence time in the secondary separator mayfacilitate more complete separation between water and a water-immisciblematerial without significantly reducing the flow rate of an aqueousstream through a clean brine system.

Although the secondary separator has been described as comprising a DGFseparator and/or a gravity separator, it should be noted that thesecondary separator may be any other type of separator known in the art.For example, the secondary separator may comprise a hydrocyclone (e.g.,a de-oiling hydrocyclone), a corrugated plate interceptor, an adsorptionmedia filter, a coalescing media filter, a membrane filter, an inducedgas flotation (IGF) separator, and/or a skimmer.

In some embodiments, the primary separator and/or secondary separatormay be configured to remove droplets of the immiscible phase havingrelatively small diameters. In certain embodiments, the primaryseparator and/or secondary separator are configured to remove dropletsof the immiscible phase having a diameter of about 200 microns or less,about 150 microns or less, about 100 microns or less, about 50 micronsor less, about 20 microns or less, about 10 microns or less, about 5microns or less, or about 1 micron or less. In certain cases, theprimary separator and/or secondary separator are configured to removedroplets of the immiscible phase having an average diameter of at leastabout 1 micron, at least about 5 microns, at least about 10 microns, atleast about 20 microns, at least about 50 microns, at least about 100microns, at least about 150 microns, or at least about 200 microns.Combinations of the above-noted ranges (e.g., about 1 micron to about200 microns, about 1 micron to about 100 microns, about 1 micron toabout 50 microns, about 1 micron to about 10 microns) are also possible.

In some embodiments, the separation apparatus comprises one or moreadditional components. According to some embodiments, the separationapparatus further comprises an optional strainer positioned upstream ofthe primary separator and/or the secondary separator. A strainergenerally refers to a device configured to prevent the passage ofparticles having a certain size through the strainer. In someembodiments, the strainer is configured to prevent the passage ofparticles having an average diameter of at least about 0.1 mm, at leastabout 0.5 mm, at least about 1 mm, at least about 2 mm, at least about 5mm, at least about 10 mm, at least about 15 mm, or at least about 20 mm.Non-limiting examples of suitable strainers include basket strainers,duplex basket strainers (e.g., twin basket strainers), Y-strainers,T-strainers, inline strainers, automatic self-cleaning strainers, platestrainers (e.g., expanded cross-section strainers), scraper strainers,and/or magnetic strainers.

In some embodiments, the separation apparatus further comprises one ormore optional buffer tanks. In some embodiments, one or more buffertanks are positioned between the primary separator and/or secondaryseparator and other components of a clean brine system.

In certain cases, the separation apparatus further comprises one or moreadditional separators. In some embodiments, the one or more separatorsare positioned upstream of the primary separator. The one or moreupstream separators may be any type of separator known in the art. Insome embodiments, the one or more upstream separators at least partiallyseparate the suspended and/or emulsified immiscible phase from water viagas flotation, gravity, centrifugal force, adsorption, and/or using abarrier. In some embodiments, the one or more upstream separatorscomprise a hydrocyclone (e.g., a de-oiling hydrocyclone), a corrugatedplate interceptor, an adsorption media filter, a coalescing mediafilter, a membrane filter, an induced gas flotation (IGF) separator, ora dissolved gas flotation (DGF) separator.

In certain embodiments, the one or more upstream separators comprise agravity separator. In some cases, the gravity separator is an AmericanPetroleum Institute (API) separator. An API separator generally refersto a separator configured to separate water and water-immisciblematerial based on the specific gravity difference between the water andwater-immiscible material (e.g., through settling). In some cases, anAPI separator may be used to separate relatively large amounts of waterand water-immiscible material. In certain embodiments, an API separatorcomprises coalescing media. In some cases, an API separator comprisesparallel plates. In certain embodiments, the presence of parallel platesin the API separator may advantageously reduce the residence timerequired for separation by settling in the API separator.

It should be noted that the primary separator, optional secondaryseparator, and/or one or more optional upstream separators may be thesame type of separator or different types of separators.

In certain embodiments, the separation apparatus can be configured toremove suspended solids. In some such embodiments, the separationapparatus can be configured to perform any of the functions describedherein with respect to the suspended solids removal apparatus. Forexample, in some such embodiments, the separation apparatus can beconfigured to remove dirt, precipitated salts, organic solids, and/orany other suspended solid material. In some embodiments, the separationapparatus can be configured to remove at least about 50%, at least about75%, at least about 90%, at least about 95%, or at least about 99% ofthe suspended solids within the stream that is transported to theseparation apparatus.

The separation apparatus may be fluidically connected to one or moreother unit operations of the clean brine system, either directly orindirectly. In some embodiments, the separation apparatus may befluidically connected to an optional ion-removal apparatus. For example,in FIG. 2A, separation apparatus 202 is fluidically connected tooptional ion-removal apparatus 204, described in more detail below, viastream 214. In some embodiments, the separation apparatus may befluidically connected to an optional suspended solids removal apparatus.For example, in FIG. 2A, separation apparatus 202 is fluidicallyconnected to optional suspended solids removal apparatus 206, describedin more detail below, via streams 214 and 218. The separation apparatusmay be, in some embodiments, fluidically connected to an optional pHadjustment apparatus. For example, in FIG. 2A, separation apparatus 202is fluidically connected to optional pH adjustment apparatus 208,described in more detail below, via streams 214, 218, and 222. In someembodiments, the separation apparatus may be fluidically connected to anoptional VOM removal apparatus. For example, in FIG. 2A, separationapparatus 202 is fluidically connected to optional VOM removal apparatus210 via streams 214, 218, 222, and 224. In some embodiments, theseparation apparatus is fluidically connected to a filtration apparatus,such as a filter press. For example, in FIG. 2A, separation apparatus202 is fluidically connected to optional filtration apparatus 212 viastreams 214, 218, and 228.

In some embodiments, the separation apparatus is directly fluidicallyconnected to an ion-removal apparatus. For example, in FIG. 2A,separation apparatus 202 is directly fluidically connected toion-removal apparatus 204, described in more detail below, via stream214. It should be understood that the invention is not limited toembodiments in which the separation apparatus is directly fluidicallyconnected to an ion-removal apparatus, and in some embodiments, theseparation apparatus can be directly fluidically connected to one ormore other unit operations. In some embodiments, the separationapparatus is directly fluidically connected to a suspended solidsremoval apparatus, described in more detail below. In certainembodiments, the separation apparatus is directly fluidically connectedto a pH adjustment apparatus, described in more detail below. Accordingto some embodiments, the separation apparatus is directly fluidicallyconnected to a VOM removal apparatus, described in more detail below. Insome embodiments, the separation apparatus is directly fluidicallyconnected to a filtration apparatus, described in more detail below.

According to certain embodiments, the clean brine system comprises anoptional ion-removal apparatus. The ion-removal apparatus can beconfigured to remove at least a portion of at least one scale-formingion from an aqueous feed stream received by the ion-removal apparatus toproduce an ion-diminished stream. Generally, the ion-diminished streamcontains less of the scale-forming ion (e.g., a scale-forming cationand/or a scale-forming anion) relative to the aqueous feed streamreceived by the ion-removal apparatus. The use of the ion-removalapparatus to remove scale-forming ions can reduce the level of scalingwithin unit operations downstream of the ion-removal apparatus.

The ion-removal apparatus can be configured to remove any scale-formingion that is desired to be removed. Those of ordinary skill in the artare familiar with scale-forming ions, which are ions that tend to formsolid scale when present in concentrations exceeding their solubilitylevels. In some cases, the scale-forming ion is a scale-forming cation(e.g., a multivalent cation). Non-limiting examples of scale-formingcations include Mg²⁺, Ca²⁺, Sr²⁺, and Ba²⁺. In some cases, at least onescale-forming ion is a scale-forming anion (e.g., a multivalent anion).Non-limiting examples of scale-forming anions include carbonate anions(CO₃ ²⁻), bicarbonate anions (HCO₃ ⁻), sulfate anions (SO₄ ²⁻),bisulfate anions (HSO₄ ⁻), and dissolved silica (e.g., SiO₂(OH)₂ ²⁻,SiO(OH)³⁻, (SiO₃ ²⁻)_(n)). In certain embodiments, the ion-removalapparatus is configured to remove at least a portion of at least onescale-forming ion in an aqueous feed stream while allowing a dissolvedmonovalent salt (e.g., NaCl) to remain dissolved in the aqueous streamtransported out of the ion-removal apparatus.

In some instances, the scale-forming ions that are removed from theaqueous feed stream using the ion-removal apparatus are sparinglysoluble (e.g., having a solubility of less than about 1 gram per 100grams of water, less than about 0.1 grams per 100 grams of water, orless than about 0.01 grams per 100 grams of water (or lower) at 20° C.).Therefore, according to some embodiments, such scale-forming ions may beprone to scaling within various parts of a water treatment system.Examples of sparingly soluble salts containing scale-forming ionsinclude, but are not limited to, calcium carbonate (CaCO₃), which has asolubility of about 0.000775 grams per 100 grams of water at 20° C.;calcium sulfate (CaSO₄), which has a solubility of about 0.264 grams per100 grams of water at 20° C.; magnesium hydroxide (Mg(OH)₂), which has asolubility of about 0.0009628 grams per 100 grams of water at 20° C.;and barium sulfate (BaSO₄), which has a solubility of about 0.000285grams per 100 grams of water at 20° C. The ion-removal apparatus can beconfigured, according to certain embodiments, such that removal of thescale-forming ions inhibits or prevents scaling of solid saltscomprising the scale-forming ions during operation of the watertreatment system.

In certain embodiments, the ion-removal apparatus is configured toproduce at least two ion-diminished streams comprising differentconcentrations of one or more scale-forming ions. In some embodiments,the ion-removal apparatus is configured to produce a firstion-diminished stream comprising a first concentration of one or morescale-forming ions and a second ion-diminished stream comprising asecond concentration of the one or more scale-forming ions. In somecases, the first concentration may be larger than the secondconcentration.

According to certain embodiments, the ion-removal apparatus isconfigured to produce a first ion-diminished stream in which theconcentration, in milligrams per liter, of at least one scale-formingion (e.g., Ca²⁺) within the first ion-diminished stream (e.g., stream106 in FIG. 1) is about 5000 mg/L or less, about 4000 mg/L or less,about 3000 mg/L or less, about 2500 mg/L or less, about 2000 mg/L orless, about 1800 mg/L or less, about 1500 mg/L or less, about 1000 mg/Lor less, about 500 mg/L or less, about 200 mg/L or less, about 100 mg/Lor less, about 50 mg/L or less, about 20 mg/L or less, about 10 mg/L orless, about 5 mg/L or less, about 2 mg/L or less, about 1 mg/L or less,or about 0.1 mg/L or less. In some embodiments, the concentration of atleast one scale-forming ion within the first ion-diminished stream is inthe range of about 0.1 mg/L to about 5000 mg/L, about 0.1 mg/L to about4000 mg/L, about 0.1 mg/L to about 3000 mg/L, about 0.1 mg/L to about2500 mg/L, about 0.1 mg/L to about 2000 mg/L, about 0.1 mg/L to about1800 mg/L, about 0.1 mg/L to about 1500 mg/L, about 0.1 mg/L to about1000 mg/L, about 0.1 mg/L to about 500 mg/L, about 0.1 mg/L to about 200mg/L, about 0.1 mg/L to about 100 mg/L, about 0.1 mg/L to about 50 mg/L,about 0.1 mg/L to about 20 mg/L, about 0.1 mg/L to about 10 mg/L, about0.1 mg/L to about 5 mg/L, about 0.1 mg/L to about 2 mg/L, or about 0.1mg/L to about 1 mg/L. In some embodiments, the first ion-diminishedstream is substantially free of at least one scale-forming ion.

In some embodiments, the ion-removal apparatus is configured to producea first ion-diminished stream in which the total concentration, inmilligrams per liter, of scale-forming ions within the firstion-diminished stream is about 5000 mg/L or less, about 4000 mg/L orless, about 3000 mg/L or less, about 2000 mg/L or less, about 1000 mg/Lor less, about 500 mg/L or less, about 200 mg/L or less, 100 mg/L orless, about 50 mg/L or less, about 20 mg/L or less, about 10 mg/L orless, about 5 mg/L or less, about 2 mg/L or less, about 1 mg/L or less,or about 0.1 mg/L or less. In some embodiments, the total concentrationof scale-forming ions within the first ion-diminished stream is in therange of about 0.1 mg/L to about 5000 mg/L, about 0.1 mg/L to about 4000mg/L, about 0.1 mg/L to about 3000 mg/L, about 0.1 mg/L to about 2000mg/L, about 0.1 mg/L to about 1000 mg/L, about 0.1 mg/L to about 500mg/L, about 0.1 mg/L to about 200 mg/L, about 0.1 mg/L to about 100mg/L, about 0.1 mg/L to about 50 mg/L, about 0.1 mg/L to about 20 mg/L,about 0.1 mg/L to about 20 mg/L, about 0.1 mg/L to about 10 mg/L, about0.1 mg/L to about 5 mg/L, about 0.1 mg/L to about 2 mg/L, or about 0.1mg/L to about 1 mg/L. In some embodiments, the first ion-diminishedstream exiting the ion-removal apparatus is substantially free ofscale-forming ions.

In certain embodiments, the ion-removal apparatus is configured toproduce a first ion-diminished stream in which the concentration, inmoles per liter (i.e., molarity), of at least one scale-forming ionwithin the first ion-diminished stream is at least about 5%, at leastabout 10%, at least about 15%, at least about 20%, at least about 25%,at least about 30%, at least about 40%, at least about 50%, at leastabout 60%, at least about 70%, or at least about 75% less than theconcentration of the at least one scale-forming ion within the streamentering the ion-removal apparatus. In certain embodiments, the sum ofthe concentrations, in moles per liter, of all scale-forming ions withinthe first ion-diminished stream is at least about 5%, at least about10%, at least about 15%, at least about 20%, at least about 25%, atleast about 30%, at least about 40%, at least about 50%, at least about60%, at least about 70%, or at least about 75% less than the sum of theconcentrations of all scale-forming ions within the stream entering theion-removal apparatus.

According to certain embodiments, the ion-removal apparatus isconfigured to produce a second ion-diminished stream in which theconcentration, in milligrams per liter, of at least one scale-formingion within the second ion-diminished stream (e.g., stream 108 in FIG. 1)is about 750 mg/L or less, about 500 mg/L or less, about 200 mg/L orless, about 100 mg/L or less, about 50 mg/L or less, about 20 mg/L orless, about 10 mg/L or less, about 5 mg/L or less, about 2 mg/L or less,about 1 mg/L or less, about 0.1 mg/L or less, or about 0 mg/L. In someembodiments, the concentration of at least one scale-forming ion withinthe second ion-diminished stream is in the range of about 0 mg/L toabout 750 mg/L, about 0 mg/L to about 500 mg/L, about 0 mg/L to about200 mg/L, about 0 mg/L to about 100 mg/L, about 0 mg/L to about 50 mg/L,about 0 mg/L to about 20 mg/L, about 0 mg/L to about 10 mg/L, about 0mg/L to about 5 mg/L, about 0 mg/L to about 2 mg/L, or about 0 mg/L toabout 1 mg/L. In some embodiments, the second ion-diminished stream issubstantially free of at least one scale-forming ion.

In some embodiments, the ion-removal apparatus is configured to producea second ion-diminished stream in which the total concentration, inmilligrams per liter, of scale-forming ions within the secondion-diminished stream is about 2600 mg/L or less, about 2500 mg/L orless, about 2000 mg/L or less, about 1800 mg/L or less, about 1500 mg/Lor less, about 1000 mg/L or less, about 900 mg/L or less, about 800 mg/Lor less, about 700 mg/L or less, about 600 mg/L or less, about 500 mg/Lor less, about 200 mg/L or less, about 100 mg/L or less, about 50 mg/Lor less, about 20 mg/L or less, about 10 mg/L or less, about 5 mg/L orless, about 2 mg/L or less, about 1 mg/L or less, about 0.1 mg/L orless, or about 0 mg/L. In some embodiments, the total concentration ofscale-forming ions within the second ion-diminished stream is in therange of about 0 mg/L to about 2600 mg/L, about 0 mg/L to about 2500mg/L, about 0 mg/L to about 2000 mg/L, about 0 mg/L to about 1800 mg/L,about 0 mg/L to about 1500 mg/L, about 0 mg/L to about 1000 mg/L, about0 mg/L to about 500 mg/L, about 0 mg/L to about 200 mg/L, about 0 mg/Lto about 100 mg/L, about 0 mg/L to about 50 mg/L, about 0 mg/L to about20 mg/L, about 0 mg/L to about 10 mg/L, about 0 mg/L to about 5 mg/L,about 0 mg/L to about 2 mg/L, or about 0 mg/L to about 1 mg/L. In someembodiments, the second ion-diminished stream exiting the ion-removalapparatus is substantially free of scale-forming ions.

In certain embodiments, the ion-removal apparatus is configured toproduce a second ion-diminished stream in which the concentration, inmoles per liter (i.e., molarity), of at least one scale-forming ionwithin the second ion-diminished stream is at least about 50%, at leastabout 75%, at least about 90%, at least about 95%, or at least about 99%less than the concentration of the at least one scale-forming ion withinthe stream entering the ion-removal apparatus. In certain embodiments,the sum of the concentrations, in moles per liter, of all scale-formingions within the second ion-diminished stream is at least about 50%, atleast about 75%, at least about 90%, at least about 95%, or at leastabout 99% less than the sum of the concentrations of all scale-formingions within the stream entering the ion-removal apparatus.

In some embodiments, the concentration, in moles per liter (i.e.,molarity), of at least one scale-forming ion within the secondion-diminished stream is at least about 5%, at least about 10%, at leastabout 20%, at least about 50%, at least about 75%, at least about 90%,or at least about 99% less than the concentration of the at least onescale forming ion within the first ion-diminished stream. In certainembodiments, the sum of the concentrations, in moles per liter, of allscale-forming ions within the second ion-diminished stream is at leastabout 5%, at least about 10%, at least about 20%, at least about 50%, atleast about 75%, at least about 90%, or at least about 99% less than thesum of the concentrations of all scale-forming ions within the firstion-diminished stream.

In some cases, the two ion-diminished streams may be suitable fordifferent purposes. In some embodiments, the first ion-diminished streammay be collected as a product stream. In certain embodiments, the firstion-diminished stream may be suitable for direct use in certainapplications. For example, in certain cases, the first ion-diminishedstream may be used as a drilling fluid and/or fracking fluid in oil andgas extraction operations. In such applications, the firstion-diminished stream may not encounter heat exchangers or other systemcomponents vulnerable to scale formation, and a relatively highconcentration of one or more scale-forming ions may be acceptable. Incertain embodiments, the second ion-diminished stream may be suitablefor further processing in a desalination system. Accordingly, in somecases, the second ion-diminished stream may be fed to a desalinationsystem to produce a substantially pure water stream having a lowerconcentration of a dissolved salt than the second ion-diminished streamand a concentrated brine stream having a higher concentration of thedissolved salt than the second ion-diminished stream. In suchprocessing, the second ion-diminished stream may come into contact withheat exchangers and other system components vulnerable to scaleformation. Accordingly, to reduce or prevent formation of scale within adesalination system, lower concentrations of one or more scale-formingions in the second ion-diminished stream may be desirable.

A variety of types of ion-removal apparatuses may be used in theembodiments described herein. In some embodiments, the ion-removalapparatus comprises a chemical ion-removal apparatus. According tocertain embodiments, the chemical ion-removal apparatus comprises one ormore ion removal compositions configured to induce precipitation of atleast one scale-forming ion. For example, the chemical ion-removalapparatus can be configured to remove at least one ion using causticsoda (e.g., NaOH), soda ash (e.g., Na₂CO₃), and/or a flocculent (e.g.,an anionic polymer). In some embodiments, the one or more ion removalcompositions can be configured to induce precipitation of at least onescale-forming cation. For example, when caustic soda and/or soda ash areadded to a stream containing Ca²⁺ and/or Mg²⁺, at least a portion ofCa²⁺ and/or Mg²⁺ contained within the stream may be precipitated as aninsoluble solid such as, for example, calcium carbonate (CaCO₃) and/ormagnesium hydroxide (Mg(OH)₂). Without wishing to be bound by aparticular theory, the addition of caustic soda may induce precipitationof certain scale-forming cations in a stream by increasing the pH of thestream. In some cases, carbonate salts and/or hydroxide salts of thescale-forming cations have relatively low solubility at relatively highpH levels, and increasing the pH of a stream containing scale-formingcations may induce precipitation of such carbonate salts and/orhydroxide salts of the scale-forming cations. In certain embodiments,the addition of soda ash may facilitate precipitation of carbonate saltsof certain scale-forming anions by providing a supply of carbonate ions.In some embodiments, the one or more ion removal compositions can beconfigured to induce precipitation of at least one scale-forming anion.

In some embodiments, the one or more ion removal compositions comprise aflocculent. A flocculent generally refers to a composition that causesrelatively large particles to form through aggregation of smallerparticles. In some embodiments, the relatively large particles mayprecipitate from a solution. Non-limiting examples of suitableflocculents include ferric chloride, polyaluminum chloride, activatedsilica, colloidal clays (e.g., bentonite), metallic hydroxides with apolymeric structure (e.g., alum, ferric hydroxide), starches and/orstarch derivatives (e.g., corn starch, potato starch, anionic oxidizedstarches, amine-treated cationic starches), polysaccharides (e.g., guargum), alginates, polyacrylamides (e.g., nonionic, anionic, or cationicpolyacrylamides), polyethylene-imines, polyamide-amines, polyamines,polyethylene oxide, and/or sulfonated compounds. Without wishing to bebound by a particular theory, certain flocculents may form largeparticles (e.g., large precipitates) by enmeshing smaller particles onformation and/or entrapping smaller particles through adhesion.

In some embodiments, the flocculent comprises a polymer. In some cases,the flocculent may be a large-chain polymer. Without wishing to be boundby a particular theory, a large-chain polymer flocculent may facilitatethe formation of large particles by adhering to a plurality of smallerparticles. In some cases, a large-chain polymer flocculent mayfacilitate the formation of large particles of increased size and/orincreased mechanical strength. In some cases, the flocculent may be ananionic polymer flocculent. In some embodiments, an anionic polymerflocculent may be used to remove scale-forming cations. In some cases,the flocculent may be a cationic polymer flocculent. In someembodiments, a cationic polymer flocculent may be used to removescale-forming anions.

It should be noted that mixtures of the above-mentioned ion removalcompositions and/or other ion removal compositions may also be used. Inaddition, if two or more ion removal compositions are added to anaqueous feed stream, the ion removal compositions may be added in anyorder. According to certain embodiments, caustic soda and a polymerflocculent (e.g., an anionic polymer flocculent) may be added to anaqueous feed stream. In certain cases, caustic soda, soda ash, and apolymer flocculent (e.g., an anionic polymer flocculent) may be added toan aqueous feed stream.

FIG. 4 shows a schematic diagram of exemplary ion-removal apparatus 204.As shown in FIG. 4, optional ion-removal apparatus 204 comprises firstreaction tank 402, second reaction tank 404, and third reaction tank406. In operation, an aqueous feed stream 214 (e.g., corresponding toimmiscible-phase-diminished stream 214 in FIGS. 2 and 3) enters optionalion-removal apparatus 204. Aqueous feed stream 214 initially entersfirst reaction tank 402. In first reaction tank 402, a first ion removalcomposition (e.g., caustic soda) may be added to stream 214 to producestream 408. Stream 408 may then be made to flow to second reaction tank404. In second reaction tank 404, a second ion removal composition(e.g., soda ash) may be added to stream 408 to produce stream 410.Stream 410 may then be made to flow to third reaction tank 406. In thirdreaction tank 406, a third ion removal composition (e.g., an anionicpolymer flocculent) may be added to stream 410 to produce ion-diminishedstream 218. In some cases, ion-diminished stream 218 may be made to flowto another unit of the clean brine system (e.g., suspended solidsremoval apparatus, pH adjustment apparatus, VOM removal apparatus,filtration apparatus) for further treatment. In certain cases,ion-diminished stream 218 may be discharged from the clean brine systemas clean brine. In some embodiments, ion-diminished stream 218 may bemade to flow to one or more storage tanks. In some cases, ion-diminishedstream 218 may be made to flow to a desalination system.

It should be noted that a chemical ion-removal apparatus may compriseany number of reaction tanks. In some embodiments, a chemicalion-removal apparatus may comprise one reaction tank, two reactiontanks, three reaction tanks, four reaction tanks, five reaction tanks,or more. In some embodiments, the residence time of an aqueous streamflowing through the reaction tanks may be relatively short. According tosome embodiments, the residence time of an aqueous stream in at leastone reaction tank is about 30 minutes or less, about 20 minutes or less,about 10 minutes or less, about 5 minutes or less, about 2 minutes orless, or about 1 minute or less. In certain embodiments, the residencetime of an aqueous stream in each reaction tank is about 30 minutes orless, about 20 minutes or less, about 10 minutes or less, about 5minutes or less, about 2 minutes or less, or about 1 minute or less. Insome embodiments, one or more of the reaction tanks comprise anagitator.

In certain embodiments, a chemical ion-removal apparatus furthercomprises an optional flocculation tank positioned downstream of one ormore reaction tanks. According to some embodiments, the flocculationtank may comprise an agitator (e.g., a slowly-rotating, low shearagitator). In some embodiments, conditions in the flocculation tank maybe selected to increase the size of precipitates formed by chemicalreactions in one or more upstream reaction tanks. For example, in somecases, a low shear agitator may be configured to promote motion ofprecipitates within the flocculation tank. In some cases, motion of theprecipitates may cause at least some of the precipitates to collide witheach other and adhere to each other, resulting in the formation oflarger precipitates. In some embodiments, it may be advantageous to havelarger precipitates, as they may have a reduced settling time. In someembodiments, the flocculation tank may have a relatively large volume.In some embodiments, the residence time of an aqueous stream in theflocculation tank may be about 60 minutes or less, about 50 minutes orless, about 40 minutes or less, about 35 minutes or less, about 30minutes or less, about 25 minutes or less, about 20 minutes or less,about 15 minutes or less, or about 10 minutes or less. In someembodiments, the residence time of an aqueous stream in the flocculationtank is in the range of about 10 minutes to about 20 minutes, about 10minutes to about 25 minutes, about 10 minutes to about 30 minutes, about10 minutes to about 35 minutes, about 10 minutes to about 40 minutes,about 10 minutes to about 50 minutes, about 10 minutes to about 60minutes, about 20 minutes to about 30 minutes, about 20 minutes to about40 minutes, about 20 minutes to about 50 minutes, about 20 minutes toabout 60 minutes, about 30 minutes to about 40 minutes, about 30 minutesto about 50 minutes, or about 30 minutes to about 60 minutes.

According to some embodiments, a chemical ion-removal apparatus may beconfigured to produce two or more ion-diminished streams by varying theamount of one or more ion removal compositions added to an aqueous feedstream. Without wishing to be bound by a particular theory, the amountof an ion removal composition added to an aqueous stream may beproportional to the amount of one or more scale-forming ionsprecipitated. In certain embodiments, relatively large amounts of one ormore scale-forming ions may be precipitated from an aqueous feed streamreceived by a chemical ion-removal apparatus by adding amounts of one ormore ion removal compositions (e.g., caustic soda) in excess of what isrequired stoichiometrically. In some cases, adding excess amounts of oneor more ion removal compositions (e.g., caustic soda) may advantageouslyspeed up reaction kinetics and result in precipitation of a relativelylarge amount of one or more scale-forming ions. Accordingly, in someembodiments, a first amount of one or more ion removal compositions maybe added to an aqueous feed stream to produce a first ion-diminishedstream having a first concentration of scale-forming ions. In someembodiments, a second, larger amount of one or more ion removalcompositions may be added to an aqueous feed stream to produce a secondion-diminished stream having a second, smaller concentration ofscale-forming ions. In some embodiments, a chemical ion-removalapparatus may be configured to produce the first ion-diminished streamand the second ion-diminished stream in an alternating manner.

In certain embodiments, the ion-removal apparatus comprises anelectrocoagulation apparatus. The electrocoagulation apparatus can beconfigured, in some embodiments, to remove at least a portion ofsuspended solids from an aqueous stream rather than, or in addition to,removing at least a portion of at least one scale-forming ion from theaqueous stream. Those of ordinary skill in the art are familiar withelectrocoagulation, in which short wave electrolysis can be used toremove at least a portion of multivalent ions and/or suspendedcontaminants.

In certain embodiments, the ion-removal apparatus comprises a resin bed.The resin bed contains, according to certain embodiments, anion-exchange resin. The resin bed can comprise, for example, ananion-selective resin bed and/or a cationic-selective resin bed. Incertain embodiments, the ion-removal apparatus comprises an ion-exchangeapparatus. The ion-exchange apparatus may contain, for example, anion-exchange medium. Those of ordinary skill in the art are familiarwith the function of ion-exchange media, which generally remove at leastone scale-forming ion from a solution and, in some but not all cases,replace the scale-forming ion(s) with one or more monovalent ion(s). Forexample, in certain embodiments, the ion-exchange medium functions bycontacting the aqueous solution containing the scale-forming ion(s),after which at least a portion of the scale-forming ions are captured bythe ion-exchange medium and at least a portion of the monovalent ionsoriginally contained within the ion-exchange medium are released intothe aqueous solution. In some such embodiments, the ion-exchange mediumcomprises an ion exchange resin.

Those of ordinary skill in the art would be capable of selecting anappropriate ion removal medium (e.g., an ion-exchange medium or otherion removal medium) for use in the ion-removal apparatus based upon thetypes of scale-forming ions dissolved in the stream fed to theion-removal apparatus, the concentration of said ions, and the flow rateat which one desires to operate the ion-removal apparatus, among otherfactors. The ion-removal apparatus can include one or more tanks and/orcolumns in which the ion removal operation is performed. For example, incertain embodiments, the ion-removal apparatus comprises one or moretanks into which an aqueous feed stream and the ion removal medium aretransported. In one set of embodiments, the aqueous feed stream and aprecipitation-inducing ion removal medium are fed to a series of tanksin which precipitation of scale-forming ions is allowed to occur. Inother embodiments, a column (e.g., a packed column) can be used toperform the ion removal operation. For example, in some embodiments, theaqueous feed stream can be fed to one or more packed columns containingan ion-exchange resin or other ion removal medium, which may be used toremove at least a portion of the scale-forming ion(s) from the aqueoussolution. One of ordinary skill in the art, given the presentdisclosure, would be capable of designing a variety of other suitableconfigurations for performing the ion removal steps described herein.

The ion-removal apparatus may be fluidically connected to one or moreother unit operations of the clean brine system, either directly orindirectly. In some embodiments, the ion-removal apparatus may befluidically connected to an optional suspended solids removal apparatus.For example, in FIG. 2A, ion-removal apparatus 204 is fluidicallyconnected to optional suspended solids removal apparatus 206, describedin more detail below, via stream 218. The ion-removal apparatus may be,in some embodiments, fluidically connected to an optional pH adjustmentapparatus. For example, in FIG. 2A, ion-removal apparatus 204 isfluidically connected to optional pH adjustment apparatus 208, describedin more detail below, via streams 218 and 222. In some embodiments, theion-removal apparatus may be fluidically connected to an optional VOMremoval apparatus. For example, in FIG. 2A, ion-removal apparatus 204 isfluidically connected to optional VOM removal apparatus 210 via streams218, 222, and 224. In some embodiments, the ion-removal apparatus isfluidically connected to a filtration apparatus (e.g., a filter press, avacuum filter). For example, in FIG. 2A, ion-removal apparatus 204 isfluidically connected to optional filtration apparatus 212 via streams218 and 228.

In some embodiments, the ion-removal apparatus is directly fluidicallyconnected to a suspended solids removal apparatus. For example, in FIG.2A, ion-removal apparatus 204 is directly fluidically connected tosuspended solids removal apparatus 206, described in more detail below,via stream 218. It should be understood that the invention is notlimited to embodiments in which the ion-removal apparatus is directlyfluidically connected to a suspended solids removal apparatus, and insome embodiments, the ion-removal apparatus can be directly fluidicallyconnected to one or more other unit operations. In some embodiments, theion-removal apparatus is directly fluidically connected to a separationapparatus. In some embodiments, the ion-removal apparatus is directlyfluidically connected to a suspended solids removal apparatus, describedin more detail below. In some embodiments, the ion-removal apparatus isdirectly fluidically connected to a pH adjustment apparatus, describedin more detail below. According to some embodiments, the ion-removalapparatus is directly fluidically connected to a VOM removal apparatus,described in more detail below. In some embodiments, the ion-removalapparatus is directly fluidically connected to a filtration apparatus,described in more detail below.

In some embodiments, the clean brine systems described herein comprisean optional suspended solids removal apparatus. The suspended solidsremoval apparatus can be configured, according to certain embodiments,to remove at least a portion of suspended solids from an aqueous feedstream received by the suspended solids removal apparatus to produce asuspended-solids-diminished stream. Generally, thesuspended-solids-diminished stream contains a smaller quantity ofsuspended solids than the input stream received by the suspended solidsremoval apparatus.

The suspended solids removal apparatus can be configured to remove anysuspended solids that may be present in the stream fed to the suspendedsolids removal apparatus. According to certain embodiments, thesuspended solids removal apparatus can be configured to remove particlesthat remain in suspension in water as a colloid or due to the motion ofthe water. In some embodiments, the suspended solids removal apparatuscan be configured to remove dirt, precipitated salts, organic solids(e.g., pathogens such as bacteria, Giardia, and the like), and/or anyother solid material. In some embodiments, the suspended solids that areremoved by the suspended solids removal apparatus comprise particulatesolids.

In certain embodiments, the suspended solids removal apparatus isconfigured to remove a relatively large percentage of the suspendedsolids from the stream fed to the suspended solids removal apparatus.For example, in some embodiments, the amount (in weight percentage, wt%) of at least one suspended solid material within the stream exitingthe suspended solids removal apparatus (e.g., stream 222 in FIG. 2) isat least about 50%, at least about 75%, at least about 90%, at leastabout 95%, or at least about 99% less than the amount of the at leastone suspended solid material within the stream entering the suspendedsolids removal apparatus (e.g., stream 218 in FIG. 2). In certainembodiments, the sum of the amounts of all suspended solid materialswithin the stream exiting the suspended solids removal apparatus is atleast about 50%, at least about 75%, at least about 90%, at least about95%, or at least about 99% less than the sum of the amounts of allsuspended solid materials within the stream entering the suspendedsolids removal apparatus.

A variety of types of devices may be used in the suspended solidsremoval apparatuses described herein. In some embodiments, the suspendedsolids removal apparatus comprises a filter, a gravity settler, and/or acoagulant-induced flocculator. A filter generally refers a deviceconfigured to inhibit passage of certain materials (e.g., particles of acertain size) from one side of the device to the other side of thedevice. A gravity settler generally refers to a device that promotesseparation of suspended solids from a liquid through gravity (e.g., asettling tank). A coagulant-induced flocculator generally refers to adevice in which a coagulant is added to a volume of liquid to induceflocculation. Non-limiting examples of coagulants include ferricchloride, alum, ferrous sulfate, ferric sulfate, ferric chloride,cationic polymer, calcium hydroxide (e.g., lime), calcium oxide (e.g.,quicklime), sodium aluminate, ferric aluminum chloride, ferric chloridesulfate, magnesium carbonate, aluminum chlorohydrate, polyaluminumchloride, polyaluminum sulfate chloride, polyaluminum silicate chloride,forms of polyaluminum chloride with organic polymers, polyferric sulfateand ferric salts with polymers, and/or polymerized aluminum-iron blends.

According to some embodiments, the gravity settler comprises aclarifier. A clarifier generally refers to a tank (e.g., a settlingtank) that is configured for substantially continuous removal of solids.In some embodiments, the clarifier is an inclined-plate clarifier (e.g.,a lamella clarifier). An inclined-plate clarifier generally refers to adevice comprising a plurality of inclined plates. In operation, anaqueous stream may enter the inclined-plate clarifier, and solidparticles may begin to settle on one or more of the inclined plates. Insome cases, when a solid particle settles on an inclined plate, itadheres to other particles that have settled on the plate, and theparticles slide down the inclined plate to the bottom of the clarifier,where they are collected as a solid-containing stream. In someembodiments, the solid-containing stream may be transported to afiltration apparatus, as described in further detail herein. In certainembodiments, the remaining water may exit the clarifier as asuspended-solids-diminished stream.

According to some embodiments, the suspended solids removal apparatuscomprises a filter. In some embodiments, the filter is a polishingfilter. A polishing filter generally refers to a filter configured toprevent passage of relatively small particles and/or remove lowconcentrations of dissolved material. Examples of a suitable polishingfilter include, but are not limited to, a granular bed filter (e.g., amedia filter) and a bag filter. A granular bed filter refers to a filterthat comprises one or more types of granular filtration media (e.g.,sand, crushed anthracite coal, garnet sand, granular activated carbon,diatomaceous earth medium). In some embodiments, the polishing filter isconfigured to remove particles having an average diameter of at leastabout 0.1 micron, at least about 0.5 micron, at least about 1 micron, atleast about 2 microns, at least about 5 microns, at least about 10microns, at least about 15 microns, at least about 20 microns, or atleast about 25 microns. In some embodiments, the polishing filter isconfigured to remove particles having an average diameter in the rangeof about 0.1 micron to about 25 microns, about 0.1 micron to about 20microns, about 0.1 micron to about 15 microns, about 0.1 micron to about10 microns, about 0.1 micron to about 5 microns, about 0.1 micron toabout 2 microns, about 0.1 micron to about 1 micron, about 0.1 micron toabout 0.5 micron, about 1 micron to about 25 microns, about 1 micron toabout 20 microns, about 1 micron to about 15 microns, about 1 micron toabout 10 microns, about 1 micron to about 5 microns, about 1 micron toabout 2 microns, about 10 microns to about 25 microns, about 10 micronsto about 20 microns, or about 10 microns to about 15 microns.

The suspended solids removal apparatus may be fluidically connected toone or more other unit operations of the clean brine system, eitherdirectly or indirectly. In some embodiments, the suspended solidsremoval apparatus may be fluidically connected to an optional pHadjustment apparatus. For example, in FIG. 2A, suspended solids removalapparatus 206 is fluidically connected to optional pH adjustmentapparatus 208, described in more detail below, via stream 222. In someembodiments, the suspended solids removal apparatus may be fluidicallyconnected to an optional VOM removal apparatus. For example, in FIG. 2A,suspended solids removal apparatus 206 is fluidically connected tooptional VOM removal apparatus 210 via streams 222 and 224. In someembodiments, the suspended solids removal apparatus is fluidicallyconnected to a filtration apparatus (e.g., a filter press, a vacuumfilter). For example, in FIG. 2A, suspended solids removal apparatus 206is fluidically connected to optional filtration apparatus 212 via stream228.

In some embodiments, the suspended solids removal apparatus is directlyfluidically connected to an ion-removal apparatus. For example, in FIG.2A, suspended solids removal apparatus 206 is directly fluidicallyconnected to ion-removal apparatus 204 via stream 218. It should beunderstood that the invention is not limited to embodiments in which thesuspended solids removal apparatus is directly fluidically connected toan ion-removal apparatus, and in some embodiments, the suspended solidsremoval apparatus can be directly fluidically connected to one or moreother unit operations. In some embodiments, the suspended solids removalapparatus is directly fluidically connected to a separation apparatus.In some embodiments, the suspended solids removal apparatus is directlyfluidically connected to an ion-removal apparatus. In some embodiments,the suspended solids removal apparatus is directly fluidically connectedto a pH adjustment apparatus, described in more detail below. Accordingto some embodiments, the suspended solids removal apparatus is directlyfluidically connected to a VOM removal apparatus, described in moredetail below. In some embodiments, the suspended solids removalapparatus is directly fluidically connected to a filtration apparatus,described in more detail below.

In certain embodiments, the clean brine apparatus comprises an optionalpH adjustment apparatus configured to receive an aqueous input streamand increase or decrease the pH of the aqueous input stream to produce apH-adjusted stream. In certain embodiments, increasing or decreasing thepH of the aqueous input stream can be performed without dissolving anyparticles that precipitated (e.g., due to addition of an ion removalcomposition in the ion-removal apparatus). In some embodiments, the pHof the aqueous input stream may be adjusted to a pH in the range ofabout 6 to about 8, about 6.5 to about 7.5, about 6.8 to about 7.2, orabout 6.9 to about 7.1. In some embodiments, the pH-adjusted stream hasa pH of about 7.0.

In some embodiments, the pH adjustment apparatus is configured to reducethe pH of the aqueous input stream. In certain embodiments, reducing thepH of the aqueous input stream can be performed in order to inhibitscale-forming ions from precipitating. In some embodiments, the pH of anaqueous feed stream may be reduced by adding a pH-adjusting compositionto the feed stream. For example, in certain embodiments, an acid may beadded to the feed stream to reduce the pH of the stream. Non-limitingexamples of suitable acids include hydrochloric acid, sulfuric acid,phosphoric acid, nitric acid, and/or maleic acid. In some embodiments, abase may be added to the feed stream to increase the pH of the stream.Non-limiting examples of suitable bases include caustic soda, potassiumhydroxide, carbon dioxide, calcium hydroxide (e.g., lime), and/orcalcium oxide (e.g., quicklime).

In some embodiments, the pH adjustment apparatus comprises one or morereaction tanks. The reaction tanks may be configured to facilitate thereaction of an aqueous stream and one or more reagents (e.g., a pHadjustment composition). In some cases, for example, one or morereaction tanks comprise a pH adjustment composition inlet and/or anagitator. In some cases, one or more reaction tanks comprise one or morepH sensors. In certain embodiments, one or more reaction tanks maycomprise two or more pH sensors. In certain cases, the pH adjustmentapparatus may further comprise a pH adjustment composition tankfluidically connected (e.g., directly fluidically connected) to one ormore reaction tanks. The pH adjustment composition tank may, forexample, be configured to contain an amount of the pH adjustmentcomposition. In some cases, the pH adjustment composition may comprisean acid (e.g., a strong acid) or a base (e.g., a strong base) having arelatively high concentration. In some cases, the pH adjustmentcomposition tank may be a double-walled tank. It may be advantageous, insome cases, for the pH adjustment composition tank to be double-walledto reduce the risk of injury in the case of a leak. For example, a leakin a first wall of a double-walled tank may be contained by the secondwall of the double-walled tank. In some cases, the pH adjustment systemfurther comprises a vapor containment system fluidically connected tothe pH adjustment composition tank. In some cases, the vapor containmentsystem may comprise a water-containing tank. In certain cases, thewater-containing tank may comprise an amount of water, and vapor fromthe pH adjustment composition tank may be bubbled through the water ofthe water-containing tank. The pH adjustment apparatus may furthercomprise one or more conduits connecting various components of the pHadjustment apparatus. In some cases, one or more conduits (e.g.,conduits connecting the pH adjustment composition tank and one or morereaction tanks) may be double-walled.

A schematic diagram of an exemplary pH adjustment apparatus is shown inFIG. 5. In FIG. 5, pH adjustment apparatus 500 comprises first reactiontank 502, second reaction tank 504, pH adjustment composition tank 506,and water-containing tank 508. In some cases, pH adjustment compositiontank 506 may be a double-walled tank, a first conduit fluidicallyconnecting pH adjustment composition tank 506 and first reaction tank502 may be a double-walled pipe, and a second conduit fluidicallyconnecting pH adjustment composition tank 506 and second reaction tank504 may be a double-walled pipe. In some cases, first reaction tank 502and/or second reaction tank 504 may comprise an agitator and/or at leastone pH sensor.

In some embodiments, a first amount of pH-adjusting composition stream234 is added to aqueous input stream 222 in first reaction tank 502 toform stream 510. Stream 510 may be directed to flow to second reactiontank 504, where a second amount of pH-adjusting composition stream 234may be added to stream 510. It should be noted that in some cases, afirst pH-adjusting composition may be added to first reaction tank 502,and a second, different pH-adjusting composition may be added to secondreaction tank 504. After an amount of a pH-adjusting composition hasbeen added to stream 510 in second reaction tank 504, the stream may bedirected to exit the pH adjustment apparatus as pH-adjusted stream 224.

In some cases, vapor from pH adjustment composition tank 506 is bubbledthrough water-containing tank 508 due to the volatility of thepH-adjusting composition. In certain embodiments, as the pH of the waterin tank 508 is decreased (e.g., the water becomes more acidic) orincreased (e.g., the water becomes more basic), the water is directed toflow to first reaction tank 502 for pH adjustment.

The pH adjustment apparatus may be fluidically connected to one or moreother unit operations of the clean brine system, either directly orindirectly. In some embodiments, the pH adjustment apparatus may befluidically connected to a VOM removal apparatus. For example, in FIG.2A, pH adjustment apparatus 208 is directly fluidically connected tooptional VOM removal apparatus 210 via stream 224. In some embodiments,the pH adjustment apparatus is fluidically connected to a filtrationapparatus (e.g., a filter press, a vacuum filter). For example, in FIG.2A, pH adjustment apparatus 208 is fluidically connected to optionalfiltration apparatus 212 via streams 222 and 228.

In some embodiments, the pH adjustment apparatus is directly fluidicallyconnected to a VOM removal apparatus. For example, in FIG. 2A, pHadjustment apparatus 208 is directly fluidically connected to VOMremoval apparatus 210, described in more detail below, via stream 224.It should be understood that the invention is not limited to embodimentsin which the pH adjustment apparatus is directly fluidically connectedto a VOM removal apparatus, and in some embodiments, the pH adjustmentapparatus can be directly fluidically connected to one or more otherunit operations. In some embodiments, the pH adjustment apparatus isdirectly fluidically connected to a separation apparatus. In someembodiments, the pH adjustment apparatus is directly fluidicallyconnected to an ion-removal apparatus. In some embodiments, the pHadjustment apparatus is directly fluidically connected to a suspendedsolids removal apparatus. In some embodiments, the pH adjustmentapparatus is directly fluidically connected to a filtration apparatus,described in more detail below.

In certain embodiments, the water treatment system comprises an optionalvolatile organic material (VOM) removal apparatus. The VOM removalapparatus can be configured to remove at least a portion of VOM from aninput stream received by the VOM removal apparatus to produce aVOM-diminished stream. Generally, the VOM-diminished stream contains VOMin an amount that is less that the amount of VOM in the input streamreceived by the VOM removal apparatus.

In certain embodiments, the volatile organic material has a boilingpoint of less than or equal to 450° C. at 1 atmosphere. VOM includesvolatile organic compounds (VOCs) and semi-volatile organic compounds(SVOCs). Examples of VOCs that can be at least partially removed by theVOM removal apparatus include, but are not limited to, acetone;1,1,1,2-tetrachloroethane; 1,1,1-trichloroethane;1,1,2,2-tetrachloroethane; 1,1,2-trichloroethane; 1,1-dichloroethane;1,1-dichloroethene; 1,1-dichloropropene; 1,2,3-trichlorobenzene;1,2,3-trichloropropane; 1,2,4-trichlorobenzene; 1,2,4-trimethylbenzene;1,2-dibromo-3-chloropropane; 1,2-dibromoethane; 1,2-dichlorobenzene;1,2-dichloroethane; 1,2-dichloropropane; 1,3,5-trimethylbenzene;1,3-dichlorobenzene; 1,3-dichloropropane; 1,4-dichlorobenzene;2,2-dichloropropane; 2-butanone; 2-chloroethyl vinyl ether;2-chlorotoluene; 2-hexanone; 4-chlorotoluene; 4-methyl-2-pentanone;benzene; bromobenzene; bromochloromethane; bromodichloromethane;bromoform; carbon disulfide; carbon tetrachloride; chlorobenzene;chloroethane; chloroform; cis-1,2-dichloroethene;cis-1,3-dichloropropene; dibromochloromethane; dibromomethane;dichlorodifluoromethane; ethylbenzene; hexachlorobutadiene;isopropylbenzene; m-xylenes; p-xylenes; bromomethane; chloromethane;methylene chloride; n-butylbenzene; n-propylbenzene; naphthalene;o-xylene; p-Isopropyltoluene; sec-butylbenzene; styrene;tert-butylbenzene; tetrachloroethene; toluene; trans-1,2-dichloroethene;trans-1,3-dichloropropene; trichloroethene; trichlorofluoromethane;vinyl acetate; and vinyl chloride. Examples of SVOCs that can be atleast partially removed by the VOM removal apparatus include, but arenot limited to, 2,4,5-trichlorophenol; 2,4,6-trichlorophenol;2,4-dichlorophenol; 2,4-dimethylphenol; 2,4-dinitrophenol;2,4-dinitrotoluene; 2,6-dinitrotoluene; 2-chloronaphthalene;2-chlorophenol; 2-methylnaphthalene; 2-methylphenol; 2-nitroaniline;2-nitrophenol; 3,3′-dichlorobenzidine; 3-nitroaniline;4,6-dinitro-2-methylphenol; 4-bromophenyl phenyl ether;4-chloro-3-methylphenol; 4-chloroaniline; 4-chlorophenyl phenyl ether; 3& 4-methylphenol; 4-nitroaniline; 4-nitrophenol; acenaphthene;acenaphthylene; anthracene; benzo(a)anthracene; benzo(a)pyrene;benzo(b)fluoranthene; benzo(g,h,i)perylene; benzo(k)fluoranthene;benzoic acid; benzyl alcohol; bis(2-chloroethoxy)methane;bis(2-chloroethyl)ether; bis(2-chloroisopropyl)ether;bis(2-ethylhexyl)phthalate; butyl benzyl phthalate; chrysene; di-n-butylphthalate; di-n-octyl phthalate; dibenz(a,h)anthracene; dibenzofuran;diethyl phthalate; dimethyl phthalate; fluoranthene; fluorene; hexachlorobenzene; hexachlorocyclopentadiene; hexachloroethane;indeno(1,2,3-cd)pyrene; isophorone; n-nitroso-di-n-propylamine;n-nitrosodiphenylamine; nitrobenzene; pentachlorophenol; phenanthrene;phenol; and pyrene.

Referring back to FIG. 2A, clean brine system 102 comprises optional VOMremoval apparatus 210. VOM removal apparatus 210 can be configured toremove at least a portion of VOM from input stream 224 received by VOMremoval apparatus 210 to produce a VOM-diminished stream 108, whichcontains less of the VOM relative to input stream 224 received by VOMremoval apparatus 210. The VOM removal apparatus can also produce astream that is enriched in VOM relative to the stream fed to the VOMremoval apparatus. For example, in FIG. 2A, VOM removal apparatus 210can be configured to produce stream 226, which is enriched in VOMrelative to stream 224.

In certain embodiments, the VOM removal apparatus is configured toremove a relatively large percentage of the VOM from the stream fed tothe VOM removal apparatus. For example, in some embodiments, the amount(in weight percentage, wt %) of at least one VOM within the streamexiting the VOM removal apparatus (e.g., stream 108 in FIG. 2) is atleast about 50%, at least about 75%, at least about 90%, at least about95%, or at least about 99% less than the amount of the at least one VOMwithin the stream entering the VOM removal apparatus (e.g., stream 224in FIG. 2). In certain embodiments, the sum of the amounts of all VOMwithin the stream exiting the VOM removal apparatus is at least about50%, at least about 75%, at least about 90%, at least about 95%, or atleast about 99% less than the sum of the amounts of all VOM within thestream entering the VOM removal apparatus.

In some embodiments, the VOM removal apparatus does not include anysources of thermal energy. For example, according to certainembodiments, the VOM removal apparatus does not include any steam inputstreams.

The VOM removal apparatus may be fluidically connected to one or moreother unit operations of the water treatment apparatus, either directlyor indirectly. In certain embodiments, the VOM removal apparatus mayalso be, in certain embodiments, fluidically connected to an optionalseparation apparatus. For example, in FIG. 2A, VOM removal apparatus 210is fluidically connected to optional separation apparatus 202 viastreams 214, 218, 222, and 224. The VOM removal apparatus may be, insome embodiments, fluidically connected to an optional ion-removalapparatus. For example, in FIG. 2A, VOM removal apparatus 210 isfluidically connected to optional ion-removal apparatus 204 via streams218, 222, and 224. In some embodiments, the VOM removal apparatus may befluidically connected to an optional suspended solids removal apparatus.For example, in FIG. 2A, VOM removal apparatus 210 is fluidicallyconnected to suspended solids removal apparatus 206 via streams 222 and224. In certain embodiments, the VOM removal apparatus may befluidically connected to an optional pH adjustment apparatus. Forexample, in FIG. 2A, VOM removal apparatus 210 is fluidically connectedto optional pH reduction apparatus 208 via stream 224. In someembodiments, the VOM removal apparatus may be fluidically connected toan optional filtration apparatus (e.g., a filter press, a vacuumfilter). For example, in FIG. 2A, VOM removal apparatus 210 isfluidically connected to optional filtration apparatus 212 via streams222, 224, and 228.

In some embodiments, the VOM removal apparatus can be directlyfluidically connected to a pH adjustment apparatus. For example, in FIG.2A, VOM removal apparatus 210 is directly fluidically connected to pHreduction apparatus 208 via stream 224. In some embodiments, the VOMremoval apparatus can be directly fluidically connected to one or moreother unit operations. In some embodiments, the VOM removal apparatus isdirectly fluidically connected to a separation apparatus. In someembodiments, the VOM removal apparatus is directly fluidically connectedto an ion-removal apparatus. In some embodiments, the VOM removalapparatus is directly fluidically connected to a suspended solidsremoval apparatus. In some embodiments, the VOM removal apparatus isdirectly fluidically connected to a filtration apparatus.

A variety of types of VOM removal apparatuses may be used in theembodiments described herein. In some embodiments, the VOM removalapparatus comprises a carbon bed filter and/or an air stripper. In someembodiments, the air stripper comprises a packed bed stripper, alow-profile air stripper, and/or an aeration stripper. In certainembodiments, the carbon bed comprises activated carbon.

According to some embodiments, the VOM removal apparatus is configuredto remove at least a portion of VOM from at least partially desalinatedwater. For example, in some embodiments, the input stream received bythe VOM removal apparatus comprises at least a portion of awater-containing stream produced by the desalination system thatcontains a lower concentration of the dissolved salt than the streamreceived by the desalination system, as described in more detail below.

According to some embodiments, the clean brine system comprises anoptional filtration apparatus. In some embodiments, the filtrationapparatus may be configured to remove at least a portion of water from asolid-containing stream to form a substantially solid material and afiltered liquid stream. The substantially solid material may, in somecases, comprise at least a portion of a precipitated salt (e.g., amonovalent salt, a divalent salt). In certain embodiments, thesubstantially solid material may be a filter cake. In some embodiments,the filter cake may comprise a plurality of solid particles, wherein atleast a portion of the solid particles are in direct contact withanother solid particle. In certain cases, at least about 60%, at leastabout 70%, at least about 80%, at least about 90%, at least about 95%,or at least about 99% of the solid particles in the filter cake are indirect contact with another solid particle. In some cases, the filtercake has a relatively low liquid content. In some embodiments, thefilter cake has a liquid content of about 90 wt % or less, about 85 wt %or less, about 80 wt % or less, about 75 wt % or less, about 70 wt % orless, about 65 wt % or less, about 60 wt % or less, about 55 wt % orless, about 50 wt % or less, about 40 wt % or less, about 30 wt % orless, about 25 wt % or less, about 20 wt % or less, about 15 wt % orless, or about 10 wt % or less. In certain embodiments, the filter cakehas a liquid content in the range of about 10 wt % to about 90 wt %,about 10 wt % to about 85 wt %, about 10 wt % to about 80 wt %, about 10wt % to about 75 wt %, about 10 wt % to about 70 wt %, about 10 wt % toabout 60 wt %, about 10 wt % to about 55 wt %, about 10 wt % to about 50wt %, about 10 wt % to about 40 wt %, about 10 wt % to about 30 wt %, orabout 10 wt % to about 20 wt %.

In some cases, the filtration apparatus comprises a filter (e.g., avacuum drum filter or a filter press) configured to at least partiallyseparate a precipitated salt from the remainder of a suspensioncontaining the precipitated salt. In some such embodiments, at least aportion of the liquid within the solid-containing stream can betransported through the filter, leaving behind solid precipitated salt(e.g., a filter cake). As one non-limiting example, a Larox FP 2016-800064/64 M40 PP/PP Filter (Outotec, Inc.) may be used as the filter. Thefilter may comprise, in certain embodiments, a conveyor filter beltwhich filters the salt from a suspension containing the salt. In somecases, for example, the filtration apparatus may be fluidicallyconnected (e.g., directly fluidically connected) to the suspended solidsremoval apparatus. For example, in certain embodiments, asolid-containing stream may be flowed (e.g., pumped) from the suspendedsolids removal apparatus (e.g., a clarifier) to the filtrationapparatus.

In some embodiments, a solid-containing stream from the suspended solidsremoval apparatus may be pumped to the filtration apparatus by one ormore pumps (e.g., air diaphragm pumps). In certain embodiments, the oneor more pumps may initially pump at a relatively low pressure and mayautomatically increase the pressure as flow rate drops due to collectionof solids in the filtration apparatus. In some cases, such a process maybe advantageous. For example, in embodiments where the filtrationapparatus comprises one or more filter presses, such a process mayadvantageously reduce filter cloth blinding (e.g., embedding ofparticles in a filter cloth) and result in formation of more consistentfilter cakes. In certain cases, a liquid component of thesolid-containing stream may be rejoined with other liquid streams in theclean brine system after passing through the filtration apparatus.

In some cases, one or more buffer tanks may be positioned between thesuspended solids removal apparatus and the filtration apparatus. Thepresence of one or more buffer tanks between the suspended solidsremoval apparatus and the filtration apparatus may, in some cases,advantageously provide buffer volume in the event that components of thefiltration apparatus (e.g., one or more filter presses) are undergoing acleaning cycle.

In some cases, a component of the filtration apparatus (e.g., a filterpress) may undergo a cleaning cycle when it is full. In certain cases, afiltration apparatus component may be considered to be full when theflow rate drops below a threshold level at a certain pumping pressure.In certain cases, when a filtration apparatus undergoes a cleaningcycle, flow may be rerouted to one or more buffer tanks to continuefluid circulation and prevent solid buildup. In some cases, the cleaningcycle begins by pumping clean brine into the filtration apparatuscomponent to flush out soft filter cake. The filtration apparatuscomponent may then be blown down. In some cases, the filter cake may bedried. For example, in certain cases, the filter cake may be air driedby blowing compressed air through the cake. It may be advantageous insome cases for the filter cake to be air dried in order to reduce itsliquid content. In some cases, compacted filter cake may be storedand/or disposed (e.g., in a dumpster).

According to certain embodiments, substantially solid material (e.g.,filter cake) produced in a clean brine system may be used to form abrine solution having a density of at least about 9 pounds/gallon. Insome cases, substantially solid material produced in a clean brinesystem may be used to form an ultra-high-density brine solution (e.g., abrine solution having a density of at least about 11.7 pounds/gallon).In certain embodiments, the brine solution has a density (e.g., measuredat about 60° F.) of at least about 9 pounds/gallon, at least about 9.5pounds/gallon, at least about 10 pounds/gallon, at least about 10.5pounds/gallon, at least about 11 pounds/gallon, at least about 11.5pounds/gallon, at least about 11.7 pounds/gallon, at least about 11.8pounds/gallon, at least about 12 pounds/gallon, at least about 12.5pounds/gallon, at least about 13 pounds/gallon, at least about 13.2pounds/gallon, at least about 13.5 pounds/gallon, at least about 14pounds/gallon, at least about 14.5 pounds/gallon, or at least about 15pounds/gallon. In some embodiments, the brine solution has a density(e.g., measured at about 60° F.) in the range of about 9 pounds/gallonto about 9.5 pounds/gallon, about 9 pounds/gallon to about 10pounds/gallon, about 9 pounds/gallon to about 10.5 pounds/gallon, about9 pounds/gallon to about 11 pounds/gallon, about 9 pounds/gallon toabout 11.7 pounds/gallon, about 9 pounds/gallon to about 11.8pounds/gallon, about 9 pounds/gallon to about 12 pounds/gallon, about 9pounds/gallon to about 12.5 pounds/gallon, about 9 pounds/gallon toabout 13 pounds/gallon, about 9 pounds/gallon to about 13.2pounds/gallon, about 9 pounds/gallon to about 13.5 pounds/gallon, about9 pounds/gallon to about 14 pounds/gallon, about 9 pounds/gallon toabout 14.5 pounds/gallon, about 9 pounds/gallon to about 15pounds/gallon, about 9.5 pounds/gallon to about 11.8 pounds/gallon,about 10 pounds/gallon to about 11 pounds/gallon, about 10 pounds/gallonto about 11.7 pounds/gallon, about 10 pounds/gallon to about 11.8pounds/gallon, about 10 pounds/gallon to about 12 pounds/gallon, about10 pounds/gallon to about 12.5 pounds/gallon, about 10 pounds/gallon toabout 13 pounds/gallon, about 10 pounds/gallon to about 13.2pounds/gallon, about 10 pounds/gallon to about 13.5 pounds/gallon, about10 pounds/gallon to about 14 pounds/gallon, about 10 pounds/gallon toabout 14.5 pounds/gallon, about 10 pounds/gallon to about 15pounds/gallon, about 10.5 pounds/gallon to about 11.8 pounds/gallon,about 11 pounds/gallon to about 11.7 pounds/gallon, about 11pounds/gallon to about 11.8 pounds/gallon, about 11 pounds/gallon toabout 12 pounds/gallon, about 11 pounds/gallon to about 12.5pounds/gallon, about 11 pounds/gallon to about 13 pounds/gallon, about11 pounds/gallon to about 13.2 pounds/gallon, about 11 pounds/gallon toabout 13.5 pounds/gallon, about 11 pounds/gallon to about 14pounds/gallon, about 11 pounds/gallon to about 14.5 pounds/gallon, about11 pounds/gallon to about 15 pounds/gallon, about 11.7 pounds/gallon toabout 12 pounds/gallon, about 11.7 pounds/gallon to about 12.5pounds/gallon, about 11.7 pounds/gallon to about 13 pounds/gallon, about11.7 pounds/gallon to about 13.2 pounds/gallon, about 11.7 pounds/gallonto about 13.5 pounds/gallon, about 11.7 pounds/gallon to about 14pounds/gallon, about 11.7 pounds/gallon to about 14.5 pounds/gallon,about 11.7 pounds/gallon to about 15 pounds/gallon, about 12pounds/gallon to about 12.5 pounds/gallon, about 12 pounds/gallon toabout 13 pounds/gallon, about 12 pounds/gallon to about 13.2pounds/gallon, about 12 pounds/gallon to about 13.5 pounds/gallon, about12 pounds/gallon to about 14 pounds/gallon, about 12 pounds/gallon toabout 14.5 pounds/gallon, about 12 pounds/gallon to about 15pounds/gallon, about 13 pounds/gallon to about 14 pounds/gallon, about13 pounds/gallon to about 14.5 pounds/gallon, about 13 pounds/gallon toabout 15 pounds/gallon, or about 14 pounds/gallon to about 15pounds/gallon.

In some cases, the density of the brine solution is measured at atemperature of about 120° F. or less, about 100° F. or less, about 80°F. or less, about 72° F. or less, about 68° F. or less, about 60° F. orless, about 50° F. or less, or about 40° F. or less. In someembodiments, the density of the brine solution is measured at atemperature of at least about 40° F., at least about 50° F., at leastabout 60° F., at least about 68° F., at least about 72° F., at leastabout 80° F., at least about 100° F., or at least about 120° F. In someembodiments, the density of the brine solution is measured at atemperature in the range of about 40° F. to about 120° F., about 40° F.to about 100° F., about 40° F. to about 80° F., about 40° F. to about72° F., about 40° F. to about 68° F., about 40° F. to about 60° F.,about 40° F. to about 50° F., about 60° F. to about 120° F., about 60°F. to about 100° F., about 60° F. to about 80° F., about 60° F. to about72° F., or about 60° F. to about 68° F.

In some cases, the brine solution comprises one or more dissolved salts.Non-limiting examples of suitable dissolved salts include sodiumchloride (NaCl), calcium chloride (CaCl₂), and/or calcium nitrate(Ca(NO₃)₂). In some cases, the brine solution has a concentration of atleast one dissolved salt of at least about 10,000 mg/L, at least about50,000 mg/L, at least about 80,000 mg/L, at least about 85,000 mg/L, atleast about 90,000 mg/L, at least about 100,000 mg/L, at least about150,000 mg/L, at least about 180,000 mg/L, at least about 200,000 mg/L,at least about 250,000 mg/L, at least about 270,000 mg/L, at least about300,000 mg/L, at least about 350,000 mg/L, at least about 380,000 mg/L,at least about 400,000 mg/L, at least about 450,000 mg/L, at least about480,000 mg/L, or at least about 500,000 mg/L. In some embodiments, thebrine solution has a concentration of at least one dissolved salt in therange of about 10,000 mg/L to about 500,000 mg/L, about 50,000 mg/L toabout 500,000 mg/L, about 80,000 mg/L to about 500,000 mg/L, about85,000 mg/L to about 500,000 mg/L, about 90,000 mg/L to about 500,000mg/L, about 100,000 mg/L to about 500,000 mg/L, about 150,000 mg/L toabout 500,000 mg/L, about 180,000 mg/L to about 500,000 mg/L, about200,000 mg/L to about 500,000 mg/L, about 250,000 mg/L to about 500,000mg/L, about 280,000 mg/L to about 500,000 mg/L, about 300,000 mg/L toabout 500,000 mg/L, about 350,000 mg/L to about 500,000 mg/L, about380,000 mg/L to about 500,000 mg/L, about 400,000 mg/L to about 500,000mg/L, or about 450,000 mg/L to about 500,000 mg/L. The concentration ofa dissolved salt generally refers to the combined concentrations of thecation and anion of the salt. For example, the concentration ofdissolved NaCl would refer to the concentration of sodium ions (Na⁺) inaddition to the concentration of chloride ions (Cl⁻). The concentrationof a dissolved salt may be measured according to any method known in theart. For example, suitable methods for measuring the concentration of adissolved salt include inductively coupled plasma (ICP) spectroscopy(e.g., inductively coupled plasma optical emission spectroscopy). As onenon-limiting example, an Optima 8300 ICP-OES spectrometer may be used.

In some cases, the brine solution has a total dissolved saltconcentration of at least about 50,000 mg/L, at least about 80,000 mg/L,at least about 85,000 mg/L, at least about 90,000 mg/L, at least about100,000 mg/L, at least about 150,000 mg/L, at least about 180,000 mg/L,at least about 200,000 mg/L, at least about 250,000 mg/L, at least about270,000 mg/L, at least about 300,000 mg/L, at least about 350,000 mg/L,at least about 380,000 mg/L, at least about 400,000 mg/L, at least about450,000 mg/L, at least about 480,000 mg/L, or at least about 500,000mg/L. In some embodiments, the brine solution has a total dissolved saltconcentration in the range of about 50,000 mg/L to about 500,000 mg/L,about 80,000 mg/L to about 500,000 mg/L, about 85,000 mg/L to about500,000 mg/L, about 90,000 mg/L to about 500,000 mg/L, about 100,000mg/L to about 500,000 mg/L, about 150,000 mg/L to about 500,000 mg/L,about 180,000 mg/L to about 500,000 mg/L, about 200,000 mg/L to about500,000 mg/L, about 250,000 mg/L to about 500,000 mg/L, about 280,000mg/L to about 500,000 mg/L, about 300,000 mg/L to about 500,000 mg/L,about 350,000 mg/L to about 500,000 mg/L, about 380,000 mg/L to about500,000 mg/L, about 400,000 mg/L to about 500,000 mg/L, or about 450,000mg/L to about 500,000 mg/L. The total dissolved salt concentrationgenerally refers to the combined concentrations of all the cations andanions of dissolved salts that are present. As a simple, non-limitingexample, in a water stream comprising dissolved NaCl and dissolvedMgSO₄, the total dissolved salt concentration would refer to the totalconcentrations of the Na⁺, Cl⁻, Me²⁺, and SO₄ ²⁻ ions. Total dissolvedsalt concentration may be measured according to any method known in theart. For example, a non-limiting example of a suitable method formeasuring total dissolved salt concentration is the SM 2540C method.According to the SM 2540C method, a sample comprising an amount ofliquid comprising one or more dissolved solids is filtered (e.g.,through a glass fiber filter), and the filtrate is evaporated to drynessin a weighed dish at 180° C. The increase in dish weight represents themass of the total dissolved solids in the sample. The total dissolvedsalt concentration of the sample may be obtained by dividing the mass ofthe total dissolved solids by the volume of the original sample.

In certain embodiments, the brine solution may be formed by adding anamount of one or more acids to at least a portion of the substantiallysolid material. Non-limiting examples of suitable acids includehydrochloric acid (HCl) and nitric acid (HNO₃).

In a particular embodiment, at least a portion of the substantiallysolid material formed in a clean brine system may comprise calciumcarbonate (CaCO₃). According to some embodiments, a concentrated brinecomprising dissolved calcium chloride (CaCl₂) may be produced by addingan amount of hydrochloric acid to the substantially solid material fromthe clean brine system. The addition of hydrochloric acid may, in somecases, result in the production of aqueous calcium chloride, water, andCO₂ (which separates from the aqueous CaCl₂ and H₂O). In some cases, abrine solution comprising dissolved CaCl₂ may be formed. In someembodiments, addition of nitric acid to a substantially solid materialcomprising calcium carbonate can produce a brine solution (e.g., anultra-high-density brine solution) comprising dissolved calcium nitrate(Ca(NO₃)₂).

According to some embodiments, the water content of the substantiallysolid material may be decreased prior to addition of an acid. Forexample, in some cases, the substantially solid material may be driedprior to addition of an acid. In certain cases, the substantially solidmaterial may be air dried (e.g, via compressed air in a filter press)prior to addition of the acid. In some cases, reducing the water contentof the substantially solid material prior to addition of the acid mayadvantageously increase the density of the resultant brine solution.

In some embodiments, an amount of a salt may be added to a brinesolution and dissolved in the brine solution. In some cases, addition ofthe additional salt may further increase the density of the brinesolution. Non-limiting examples of suitable salts include sodiumchloride (NaCl), calcium chloride (CaCl₂), magnesium chloride (MgCl₂),copper (II) chloride (CuCl₂), iron (III) chloride hexahydrate(FeCl₃.6H₂O), iron (III) chloride (FeCl₃), lithium chloride (LiCl),manganese (II) chloride (MnCl₂), nickel (II) chloride (NiCl₂), zincchloride (ZnCl₂), calcium bromide (CaBr₂), magnesium bromide (MgBr₂),potassium bromide (KBr), sodium bromide (NaBr), copper (II) bromide(CuBr₂), iron (III) bromide (FeBr₃), lithium bromide (LiBr), manganese(II) bromide (MnBr₂), nickel (II) bromide (NiBr₂), zinc bromide (ZnBr₂),ammonium nitrate (NH₄NO₃), sodium nitrate (NaNO₃), lithium nitrate(LiNO₃), calcium nitrate (Ca(NO₃)₂), magnesium nitrate (Mg(NO₃)₂),strontium nitrate (Sr(NO₃)₂), calcium nitrate tetrahydrate(Ca(NO₃)₂.4H₂O), copper (II) nitrate (Cu(NO₃)₂), iron (II) nitrate(Fe(NO₃)₂), iron (III) nitrate (Fe(NO₃)₃), nickel (II) nitrate(Ni(NO₃)₂), and/or zinc nitrate (Zn(NO₃)₂). In some embodiments, atleast one of the one or more additional salts added to a brine solutioncomprising water and at least one dissolved salt is different from theat least one dissolved salt. In some embodiments, each of the one ormore additional salts added to the brine solution is different from theat least one dissolved salt. In certain cases, at least one of the oneor more additional salts added to the brine solution is the same as theat least one dissolved salt.

In certain embodiments, the brine solution with additional salt has adensity (e.g., measured at about 60° F.) of at least about 11pounds/gallon, at least about 11.5 pounds/gallon, at least about 11.7pounds/gallon, at least about 12 pounds/gallon, at least about 12.5pounds/gallon, at least about 13 pounds/gallon, at least about 13.2pounds/gallon, at least about 13.5 pounds/gallon, at least about 14pounds/gallon, at least about 14.5 pounds/gallon, at least about 15pounds/gallon, at least about 20 pounds/gallon, or at least about 25pounds/gallon. In certain cases, the brine solution with additional salthas a density (e.g., measured at about 60° F.) in the range of about 11pounds/gallon to about 12 pounds/gallon, about 11 pounds/per gallon toabout 12.5 pounds/gallon, about 11 pounds/gallon to about 13pounds/gallon, about 11 pounds/gallon to about 13.2 pounds/gallon, about11 pounds/gallon to about 13.5 pounds/gallon, about 11 pounds/gallon toabout 14 pounds/gallon, about 11 pounds/gallon to about 14.5pounds/gallon, about 11 pounds/gallon to about 15 pounds/gallon, about11 pounds/gallon to about 20 pounds/gallon, about 11 pounds/gallon toabout 25 pounds/gallon, about 11.5 pounds/gallon to about 12pounds/gallon, about 11.5 pounds/gallon to about 12.5 pounds/gallon,about 11.5 pounds/gallon to about 13 pounds/gallon, about 11.5pounds/gallon to about 13.2 pounds/gallon, about 11.5 pounds/gallon toabout 13.5 pounds/gallon, about 11.5 pounds/gallon to about 14pounds/gallon, about 11.5 pounds/gallon to about 14.5 pounds/gallon,about 11.5 pounds/gallon to about 15 pounds/gallon, about 11.5pounds/gallon to about 20 pounds/gallon, about 11.5 pounds/gallon toabout 25 pounds/gallon, about 11.7 pounds/gallon to about 12.5pounds/gallon, about 11.7 pounds/gallon to about 13 pounds/gallon, about11.7 pounds/gallon to about 13.2 pounds/gallon, about 11.7 pounds/gallonto about 13.5 pounds/gallon, about 11.7 pounds/gallon to about 14pounds/gallon, about 11.7 pounds/gallon to about 14.5 pounds/gallon,about 11.7 pounds/gallon to about 15 pounds/gallon, about 11.7pounds/gallon to about 20 pounds/gallon, about 11.7 pounds/gallon toabout 25 pounds/gallon, or about 12 pounds/gallon to about 12.5pounds/gallon, about 12 pounds/gallon to about 13 pounds/gallon, about12 pounds/gallon to about 13.2 pounds/gallon, about 12 pounds/gallon toabout 13.5 pounds/gallon, about 12 pounds/gallon to about 14pounds/gallon, about 12 pounds/gallon to about 14.5 pounds/gallon, about12 pounds/gallon to about 15 pounds/gallon, about 12 pounds/gallon toabout 20 pounds/gallon, about 12 pounds/gallon to about 25pounds/gallon, about 13 pounds/gallon to about 13.5 pounds/gallon, about13 pounds/gallon to about 14 pounds/gallon, about 13 pounds/gallon toabout 14.5 pounds/gallon, about 13 pounds/gallon to about 15pounds/gallon, about 13 pounds/gallon to about 20 pounds/gallon, about13 pounds/gallon to about 25 pounds/gallon, about 14 pounds/gallon toabout 15 pounds/gallon, about 14 pounds/gallon to about 20pounds/gallon, about 14 pounds/gallon to about 25 pounds/gallon, about15 pounds/gallon to about 20 pounds/gallon, about 15 pounds/gallon toabout 25 pounds/gallon, or about 20 pounds/gallon to about 25pounds/gallon.

In some cases, the density of the brine solution with additional salt ismeasured at a temperature of about 120° F. or less, about 100° F. orless, about 80° F. or less, about 72° F. or less, about 68° F. or less,about 60° F. or less, about 50° F. or less, or about 40° F. or less. Insome embodiments, the density of the brine solution with additional saltis measured at a temperature of at least about 40° F., at least about50° F., at least about 60° F., at least about 68° F., at least about 72°F., at least about 80° F., at least about 100° F., or at least about120° F. In some embodiments, the density of the brine solution withadditional salt is measured at a temperature in the range of about 40°F. to about 120° F., about 40° F. to about 100° F., about 40° F. toabout 80° F., about 40° F. to about 72° F., about 40° F. to about 68°F., about 40° F. to about 60° F., about 40° F. to about 50° F., about60° F. to about 120° F., about 60° F. to about 100° F., about 60° F. toabout 80° F., about 60° F. to about 72° F., or about 60° F. to about 68°F.

It may be advantageous, in certain cases, to form a brine solution fromthe substantially solid material formed in the clean brine system. Insome cases, the brine solution may be used in various applications(e.g., as a kill fluid in oil and gas operations). In some embodiments,the formation of a brine solution may avoid the expensive disposal of asolid material. According to some embodiments, substantially no solidmaterial is discharged from the clean brine system. In certain cases,approximately about 70%, about 80%, about 90%, about 95%, about 99% orabout 100% by weight of the material discharged from the clean brinesystem is substantially a liquid or a gas. In some embodiments, at leastabout 70%, at least about 80%, at least about 90%, at least about 95%,at least about 99%, or about 100% by weight of the substantially solidmaterial is dissolved to form a brine solution. In certain embodiments,substantially all of the substantially solid material formed by theclean brine system is dissolved to form a brine solution.

In some cases, CO₂ resulting from the reaction of the solid material andHCl may be collected. In some cases, the CO₂ may advantageously be usedto increase the alkalinity of an aqueous feed stream prior to the ionremoval step, reducing the amount of soda ash required. In some cases,the CO₂ may be used to decrease the pH of the feed stream prior to thepH adjustment step, reducing the amount of additional acid (e.g., HCl)required.

According to some embodiments, at least one component of the clean brinesystem is fluidically connected to at least one storage tank. A storagetank generally refers to any vessel (e.g., stainless steel tank or othervessel) that may be used to store a liquid. The storage tank may haveany shape (e.g, substantially cylindrical, substantially rectangularprismatic, and the like) and any size. In some embodiments, the storagetank may store an amount of liquid (e.g., clean brine) until the liquidcan be used in an application (e.g., an oil or gas extraction process).In certain cases, the storage tank may be fluidically connected (e.g.,directly fluidically connected) to one or more water treatment systems(e.g., a desalination system downstream of the clean brine system).

In some embodiments, at least one storage tank is fluidically connectedto at least one component of the clean brine system. In certain cases,at least one storage tank is directly fluidically connected to at leastone component of the clean brine system. In certain embodiments, atleast one storage tank is fluidically connected to at least onecomponent of the clean brine system such that no interveningdesalination system is fluidically connected between the storage tankand the component. In certain embodiments, at least one storage tank isfluidically connected to at least one component of the clean brinesystem such that no intervening precipitation apparatus (e.g.,crystallization tank) is fluidically connected between the storage tankand the component. In some embodiments, at least one storage tank isfluidically connected to at least one component of the clean brinesystem such that no humidifier and/or dehumidifier is fluidicallyconnected between the storage tank and the component.

In some embodiments, at least one storage tank is fluidically connectedto a separation apparatus of the clean brine system. In some cases, atleast one storage tank is directly fluidically connected to theseparation apparatus. In some embodiments, at least one storage tank isfluidically connected to the separation apparatus such that nointervening desalination system is fluidically connected between thestorage tank and the separation apparatus. In some embodiments, at leastone storage tank is fluidically connected to the separation apparatussuch that no intervening precipitation apparatus (e.g., crystallizationtank) is fluidically connected between the storage tank and theseparation apparatus. In some embodiments, at least one storage tank isfluidically connected to the separation apparatus such that nohumidifier and/or dehumidifier is fluidically connected between thestorage tank and the separation apparatus.

In some embodiments, at least one storage tank is fluidically connectedto an ion-removal apparatus of the clean brine system. In some cases, atleast one storage tank is directly fluidically connected to theion-removal apparatus. In some embodiments, at least one storage tank isfluidically connected to the ion-removal apparatus such that nointervening desalination system is fluidically connected between thestorage tank and the ion-removal apparatus. In some embodiments, atleast one storage tank is fluidically connected to the ion-removalapparatus such that no intervening precipitation apparatus (e.g.,crystallization tank) is fluidically connected between the storage tankand the ion-removal apparatus. In some embodiments, at least one storagetank is fluidically connected to the ion-removal apparatus such that nohumidifier and/or dehumidifier is fluidically connected between thestorage tank and the ion-removal apparatus.

In some embodiments, at least one storage tank is fluidically connectedto a suspended solids removal apparatus of the clean brine system. Insome cases, at least one storage tank is directly fluidically connectedto the suspended solids removal apparatus. In some embodiments, at leastone storage tank is fluidically connected to the suspended solidsremoval apparatus such that no intervening desalination system isfluidically connected between the storage tank and the suspended solidsremoval apparatus. In some embodiments, at least one storage tank isfluidically connected to the suspended solids removal apparatus suchthat no intervening precipitation apparatus (e.g., crystallization tank)is fluidically connected between the storage tank and the suspendedsolids removal apparatus. In some embodiments, at least one storage tankis fluidically connected to the suspended solids removal apparatus suchthat no humidifier and/or dehumidifier is fluidically connected betweenthe storage tank and the suspended solids removal apparatus.

In some embodiments, at least one storage tank is fluidically connectedto a pH adjustment apparatus of the clean brine system. In some cases,at least one storage tank is directly fluidically connected to the pHadjustment apparatus. In some embodiments, at least one storage tank isfluidically connected to the pH adjustment apparatus such that nointervening desalination system is fluidically connected between thestorage tank and the pH adjustment apparatus. In some embodiments, atleast one storage tank is fluidically connected to the pH adjustmentapparatus such that no intervening precipitation apparatus (e.g.,crystallization tank) is fluidically connected between the storage tankand the pH adjustment apparatus. In some embodiments, at least onestorage tank is fluidically connected to the pH adjustment apparatussuch that no humidifier and/or dehumidifier is fluidically connectedbetween the storage tank and the pH adjustment apparatus.

In some embodiments, at least one storage tank is fluidically connectedto a VOM removal apparatus of the clean brine system. In some cases, atleast one storage tank is directly fluidically connected to the VOMremoval apparatus. In some embodiments, at least one storage tank isfluidically connected to the VOM removal apparatus such that nointervening desalination system is fluidically connected between thestorage tank and the VOM removal apparatus. In some embodiments, atleast one storage tank is fluidically connected to the VOM removalapparatus such that no intervening precipitation apparatus (e.g.,crystallization tank) is fluidically connected between the storage tankand the VOM removal apparatus. In some embodiments, at least one storagetank is fluidically connected to the VOM removal apparatus such that nohumidifier and/or dehumidifier is fluidically connected between thestorage tank and the VOM removal apparatus.

In some embodiments, at least one storage tank is fluidically connectedto a filtration apparatus of the clean brine system. In some cases, atleast one storage tank is directly fluidically connected to thefiltration apparatus. In some embodiments, at least one storage tank isfluidically connected to the filtration apparatus such that nointervening desalination system is fluidically connected between thestorage tank and the filtration apparatus. In some embodiments, at leastone storage tank is fluidically connected to the filtration apparatussuch that no intervening precipitation apparatus (e.g., crystallizationtank) is fluidically connected between the storage tank and thefiltration apparatus. In some embodiments, at least one storage tank isfluidically connected to the filtration apparatus such that nohumidifier and/or dehumidifier is fluidically connected between thestorage tank and the filtration apparatus.

While separation apparatus 202, ion-removal apparatus 204, suspendedsolids removal apparatus 206, pH adjustment apparatus 208, and VOMremoval apparatus 210 are shown in FIG. 2A as being arranged in aparticular order, it should be understood that in other embodiments,these components may be alternatively arranged.

In certain embodiments, the input stream received by the ion-removalapparatus comprises at least a portion of theimmiscible-phase-diminished stream produced by the separation apparatus.That is to say, in certain embodiments, the ion-removal apparatus can belocated downstream of the separation apparatus. Referring to FIG. 2A,ion-removal apparatus 204 receives at least a portion ofimmiscible-phase-diminished stream 214 produced by separation apparatus202. In other embodiments, the input stream received by the separationapparatus comprises at least a portion of the ion-diminished streamproduced by the ion-removal apparatus. That is to say, in certainembodiments, the separation apparatus can be located downstream of theion-removal apparatus.

In some embodiments, for example, the input stream received by thesuspended solids removal apparatus comprises at least a portion of theimmiscible-phase-diminished stream produced by the separation apparatus.That is to say, in certain embodiments, the suspended solids removalapparatus can be located downstream of the separation apparatus.Referring to FIG. 2A, for example, input stream 218 received bysuspended solids removal apparatus 206 comprises at least a portion ofthe immiscible-phase-diminished stream (e.g., stream 214) produced byseparation apparatus 202. In other embodiments, the input streamreceived by the separation apparatus comprises at least a portion of thesuspended-solids-diminished stream produced by the suspended solidsremoval apparatus. That is to say, in certain embodiments, theseparation apparatus can be located downstream of the suspended solidsremoval apparatus.

In certain embodiments, the input stream received by the pH adjustmentapparatus comprises at least a portion of theimmiscible-phase-diminished stream produced by the separation apparatus.That is to say, in certain embodiments, the pH adjustment apparatus canbe located downstream of the separation apparatus. Referring to FIG. 2A,for example, input stream 222 received by pH adjustment apparatus 208comprises at least a portion of immiscible-phase-diminished stream 214produced by separation apparatus 202. In other embodiments, the inputstream received by the separation apparatus comprises at least a portionof the pH-adjusted stream produced by the pH adjustment apparatus. Thatis to say, in certain embodiments, the separation apparatus can belocated downstream of the pH adjustment apparatus.

In some embodiments, the input stream received by the volatile organicmaterial (VOM) removal apparatus comprises at least a portion of theimmiscible-phase-diminished stream produced by the separation apparatus.That is to say, in certain embodiments, the VOM removal apparatus can belocated downstream of the separation apparatus. Referring to FIG. 2A,for example, input stream 224 received by VOM removal apparatus 210comprises at least a portion of immiscible-phase-diminished stream 214produced by separation apparatus 202. In other embodiments, the inputstream received by the separation apparatus comprises at least a portionof the VOM-diminished stream produced by the VOM removal apparatus. Thatis to say, in certain embodiments, the separation apparatus can belocated downstream of the VOM removal apparatus.

In certain embodiments, the input stream received by the suspendedsolids removal apparatus comprises at least a portion of theion-diminished stream produced by the ion-removal apparatus. That is tosay, in certain embodiments, the suspended solids removal apparatus canbe located downstream of the ion-removal apparatus. Referring to FIG.2A, for example, input stream 218 received by suspended solids removalapparatus 206 comprises at least a portion of ion-diminished stream(also stream 218) produced by ion-removal apparatus 204. In otherembodiments, the input stream received by the ion-removal apparatuscomprises at least a portion of the suspended-solids-diminished streamproduced by the suspended solids removal apparatus. That is to say, incertain embodiments, the ion-removal apparatus can be located downstreamof the suspended solids removal apparatus.

In certain embodiments, the input stream received by the pH adjustmentapparatus comprises at least a portion of the ion-diminished streamproduced by the ion-removal apparatus. That is to say, in certainembodiments, the pH adjustment apparatus can be located downstream ofthe ion-removal apparatus. Referring to FIG. 2A, for example, inputstream 222 received by pH adjustment apparatus 208 comprises at least aportion of ion-diminished stream 218 produced by ion-removal apparatus204. In other embodiments, the input stream received by the ion-removalapparatus comprises at least a portion of the pH-adjusted streamproduced by the pH adjustment apparatus. That is to say, in certainembodiments, the ion-removal apparatus can be located downstream of thepH adjustment apparatus.

In some embodiments, the input stream received by the VOM removalapparatus comprises at least a portion of the ion-diminished streamproduced by the ion-removal apparatus. That is to say, in certainembodiments, the VOM removal apparatus can be located downstream of theion-removal apparatus. Referring to FIG. 2A, for example, input stream224 received by VOM removal apparatus 210 comprises at least a portionof ion-diminished stream 218 produced by ion-removal apparatus 204. Inother embodiments, the input stream received by the ion-removalapparatus comprises at least a portion of the VOM-diminished streamproduced by the VOM removal apparatus. That is to say, in certainembodiments, the ion-removal apparatus can be located downstream of theVOM removal apparatus.

In certain embodiments, the input stream received by the pH adjustmentapparatus comprises at least a portion of thesuspended-solids-diminished stream produced by the suspended solidsremoval apparatus. That is to say, in certain embodiments, the pHadjustment apparatus can be located downstream of the suspended solidsremoval apparatus. Referring to FIG. 2A, for example, input stream 222received by pH adjustment apparatus 208 comprises at least a portion ofsuspended-solids-diminished stream 222 produced by suspended solidsremoval apparatus 206. In other embodiments, the input stream receivedby the suspended solids removal apparatus comprises at least a portionof the pH-adjusted stream produced by the pH adjustment apparatus. Thatis to say, in certain embodiments, the suspended solids removalapparatus can be located downstream of the pH adjustment apparatus.

In some embodiments, the input stream received by the VOM removalapparatus comprises at least a portion of thesuspended-solids-diminished stream produced by the suspended solidsremoval apparatus. That is to say, in certain embodiments, the VOMremoval apparatus can be located downstream of the suspended solidsremoval apparatus. Referring to FIG. 2A, for example, input stream 224received by VOM removal apparatus 210 comprises at least a portion ofsuspended solids-diminished stream 222 produced by suspended solidsremoval apparatus 206. In other embodiments, the input stream receivedby the suspended solids removal apparatus comprises at least a portionof the VOM-diminished stream produced by the VOM removal apparatus. Thatis to say, in certain embodiments, the suspended solids removalapparatus can be located downstream of the VOM removal apparatus.

In some embodiments, the input stream received by the VOM removalapparatus comprises at least a portion of the pH-adjusted streamproduced by the pH adjustment apparatus. That is to say, in certainembodiments, the VOM removal apparatus can be located downstream of thepH adjustment apparatus. Referring to FIG. 2A, for example, input stream224 received by VOM removal apparatus 210 comprises at least a portionof pH-adjusted stream (also stream 224) produced by pH adjustmentapparatus 208. In other embodiments, the input stream received by the pHadjustment apparatus comprises at least a portion of the VOM-diminishedstream produced by the VOM removal apparatus. That is to say, in certainembodiments, the pH adjustment apparatus can be located downstream ofthe VOM removal apparatus.

Each of separation apparatus 202, ion-removal apparatus 204, suspendedsolids removal apparatus 206, pH adjustment apparatus 208, VOM removalapparatus 210, and filtration apparatus 212 is an optional feature ofthe clean brine system. In some embodiments, the clean brine systemcomprises only one of separation apparatus 202, ion-removal apparatus204, suspended solids removal apparatus 206, pH adjustment apparatus208, VOM removal apparatus 210, and/or filtration apparatus 212. In someembodiments, the clean brine system comprises any combination of two ormore of separation apparatuses 202, suspended solids removal apparatuses206, ion-removal apparatuses 204, pH adjustment apparatuses 208, VOMremoval apparatuses 210, and/or filtration apparatuses 212.

Various of the unit operations described herein can be “directlyfluidically connected” to other unit operations and/or components. Asused herein, a direct fluid connection exists between a first unitoperation and a second unit operation (and the two unit operations aresaid to be “directly fluidically connected” to each other) when they arefluidically connected to each other and the composition of the fluiddoes not substantially change (i.e., no fluid component changes inrelative abundance by more than 5% and no phase change occurs) as it istransported from the first unit operation to the second unit operation.As an illustrative example, a stream that connects first and second unitoperations, and in which the pressure and temperature of the fluid isadjusted but the composition of the fluid is not altered, would be saidto directly fluidically connect the first and second unit operations.If, on the other hand, a separation step is performed and/or a chemicalreaction is performed that substantially alters the composition of thestream contents during passage from the first component to the secondcomponent, the stream would not be said to directly fluidically connectthe first and second unit operations.

It should be understood that, in embodiments in which a single unit isshown in the figures and/or is described as performing a certainfunction, the single unit could be replaced with multiple units (e.g.,operated in parallel) performing a similar function. For example, incertain embodiments, any one or more of the separation apparatus,suspended solids removal apparatus, ion-removal apparatus, pH adjustmentapparatus, VOM removal apparatus, filtration apparatus, and/ordesalination system could correspond to a plurality of separationapparatuses, suspended solids removal apparatuses, ion-removalapparatuses, pH adjustment apparatuses, VOM removal apparatuses,filtration apparatuses, and/or desalination systems (e.g., configured tobe operated in parallel).

It should also be understood that, where separate units are shown in thefigures and/or described as performing a sequence of certain functions,the units may also be present as a single unit (e.g., within a commonhousing), and the single unit may perform a combination of functions.For example, in some embodiments, any two or more of the separationapparatus, the ion-removal apparatus, the suspended solids removalapparatus, the pH adjustment apparatus, the VOM removal apparatus, andthe filtration apparatus can be a single unit which can perform each ofthe functions associated with the combination.

As particular examples, in some embodiments, the system comprises asingle unit that acts as both an ion-removal apparatus and a separationapparatus. In certain embodiments, the system comprises a single unitthat acts as both an ion-removal apparatus and a suspended solidsremoval apparatus. In certain embodiments, the system comprises a singleunit that acts as both an ion-removal apparatus and a pH adjustmentapparatus. In certain embodiments, the system comprises a single unitthat acts as both an ion-removal apparatus and a VOM removal apparatus.As additional examples, in some embodiments, the system comprises asingle unit that acts as both a separation apparatus and a suspendedsolids removal apparatus. In some embodiments, the system comprises asingle unit that acts as both a separation apparatus and an ion-removalapparatus. In certain embodiments, the system comprises a single unitthat acts as both a separation apparatus and a pH adjustment apparatus.In certain embodiments, the system comprises a single unit that acts asboth a separation apparatus and a VOM removal apparatus. As stillfurther examples, in some embodiments, the system comprises a singleunit that acts as both a suspended solids removal apparatus and a pHadjustment apparatus. In some embodiments, the system comprises a singleunit that acts as both a suspended solids removal apparatus and a VOMremoval apparatus. In some embodiments, the system comprises a singleunit that acts as both a pH adjustment apparatus and a VOM removalapparatus. Units that perform three, four, or five of the functionsoutlined above are also possible. Of course, the invention is notnecessarily limited to combination units, and in some embodiments, anyof the separation apparatus, the suspended solids removal apparatus, theion-removal apparatus, the pH adjustment apparatus, the VOM removalapparatus, and/or the filtration apparatus may be standalone units.

In some embodiments, one or more aqueous streams (e.g., clean brinestreams) produced by a clean brine system described herein may becollected as product streams. In some cases, one or more aqueous streamsproduced by the clean brine system may be further treated, for exampleby a desalination system. However, it should be noted that any furtherprocessing of a clean brine stream by a downstream system (e.g., adesalination system) is optional. That is to say, in some embodiments,the clean brine system may be used in association with a downstreamapparatus, but in other embodiments, the clean brine system may be usedon its own, in the absence of any downstream systems.

Desalination

In some embodiments, the water treatment system comprises an optionaldesalination system fluidically connected to the clean brine system. Insome embodiments, the desalination system is configured to remove waterfrom an aqueous stream received by the desalination system to produce aconcentrated brine stream enriched in a salt (e.g., a dissolved salt)relative to the aqueous stream received by the desalination system. Incertain embodiments, the desalination system is also configured toproduce a substantially pure water stream lean in a dissolved saltrelative to the aqueous stream received by the desalination system. Insome embodiments, the desalination system is a system configured toremove at least a portion of at least one dissolved salt from an aqueousstream.

According to some embodiments, at least one salt in an aqueous streamreceived by the desalination system is a dissolved salt (e.g., a saltthat has been solubilized to such an extent that the component ions ofthe salt are no long ionically bonded to each other). In certainembodiments, at least one salt in the liquid stream is a monovalentsalt. As used herein, the term “monovalent salt” refers to a salt thatincludes a monovalent cation (e.g., a cation with a redox state of +1when solubilized). Examples of monovalent salts include, but are notlimited to, salts containing sodium, potassium, lithium, rubidium,cesium, and francium. In certain embodiments, the monovalent saltsinclude monovalent anions comprising, for example, chlorine, bromine,fluorine, and iodine. Non-limiting examples of monovalent salts includesodium chloride (NaCl), sodium bromide (NaBr), potassium chloride (KCl),potassium bromide (KBr), sodium carbonate, (Na₂CO₃), and sodium sulfate(Na₂SO₄). In some cases, at least one salt is a divalent salt. As usedherein, the term “divalent salt” refers to a salt that includes adivalent cation (e.g., a cation with a redox state of +2 whensolubilized). Non-limiting examples of divalent salts include calciumchloride (CaCl₂), calcium sulfate (CaSO₄), magnesium sulfate (MgSO₄),strontium sulfate (SrSO₄), barium sulfate (BaSO₄), and/orbarium-strontium sulfate (BaSr(SO₄)₂). In some cases, at least one saltin the liquid stream is a trivalent salt (e.g., a salt that includes atrivalent cation having a redox state of +3 when solubilized) or atetravalent salt (e.g., a salt that includes a tetravalent cation havinga redox state of +4 when solubilized). Non-limiting examples oftrivalent salts or tetravalent salts include iron (III) hydroxide(Fe(OH)₃), iron (III) carbonate (Fe₂(CO₃)₃), aluminum hydroxide(Al(OH)₃), aluminum carbonate (Al₂(CO₃)₃), boron salts, and/orsilicates.

In some embodiments, the desalination system is a thermal desalinationsystem. According to certain embodiments, the desalination system is ahumidification-dehumidification (HDH) desalination system. An HDHdesalination system generally refers to a system comprising a humidifierand a dehumidifier. In some embodiments, the humidifier is configured toreceive a liquid feed stream comprising water and at least one dissolvedsalt and to transfer at least a portion of the water from the liquidfeed stream to a carrier gas through an evaporation process, therebyproducing a humidified gas stream and a concentrated brine stream. Incertain embodiments, the carrier gas comprises a non-condensable gas.Non-limiting examples of suitable non-condensable gases include air,nitrogen, oxygen, helium, argon, carbon monoxide, carbon dioxide, sulfuroxides (SO_(x)) (e.g., SO₂, SO₃), and/or nitrogen oxides (NO_(x)) (e.g.,NO, NO₂). In some embodiments, the dehumidifier is configured to receivethe humidified gas stream from the humidifier and to transfer at least aportion of water from the humidified gas stream to a stream comprisingsubstantially pure water through a condensation process.

FIG. 6 shows an exemplary schematic illustration of HDH desalinationsystem 600, which may be used in association with certain inventivesystems and methods described herein. In FIG. 6, desalination system 600comprises humidifier 602 and dehumidifier 604. As shown in FIG. 6,humidifier 602 comprises liquid inlet 606 and liquid outlet 608. In FIG.6, humidifier 602 is fluidically connected to dehumidifier 604 via gasconduits 610 and 612. As shown in FIG. 6, dehumidifier 604 comprisesliquid inlet 614 and liquid outlet 616.

In operation, a liquid stream comprising water and a dissolved salt atan initial concentration may enter humidifier 602 through liquid inlet606. Humidifier 602 may also be configured to receive a carrier gasstream comprising a non-condensable gas. According to some embodiments,humidifier 602 is configured such that the liquid stream comes intocontact (e.g., direct or indirect contact) with the carrier gas stream,and heat and water vapor are transferred from the liquid stream to thecarrier gas stream through an evaporation process, thereby producing ahumidified gas stream. In some embodiments, the remaining portion of theliquid stream that is not transported to the carrier gas stream forms aconcentrated brine stream enriched in the dissolved salt relative to theliquid stream (e.g., the concentration of the dissolved salt in theconcentrated brine stream is greater than the initial concentration ofthe dissolved salt in the liquid stream). In some embodiments, theconcentrated brine stream exits humidifier 602 through liquid outlet608.

According to some embodiments, the humidified gas stream exitshumidifier 602 and flows through gas conduit 610 to dehumidifier 604. Astream comprising substantially pure water may enter dehumidifier 604through liquid inlet 614. In dehumidifier 604, the humidified gas streammay come into contact (e.g., direct or indirect contact) with thesubstantially pure water stream, and heat and water may be transferredfrom the humidified gas stream to the substantially pure water streamthrough a condensation process, thereby producing a dehumidified gasstream. The stream comprising substantially pure water may exitdehumidifier 604 through liquid outlet 616; in some cases, at least aportion of the substantially pure water stream may be discharged fromHDH desalination system 600, and at least a portion of the substantiallypure water stream may be recirculated to liquid inlet 614. Thedehumidified gas stream may exit dehumidifier 604, and at least aportion of the dehumidified gas stream may flow to humidifier 602through gas conduit 612. In some embodiments, at least a portion of thedehumidified gas stream may be transported elsewhere within the systemand/or vented.

The humidifier may have any configuration that allows for the transferof water vapor from a liquid feed stream to a carrier gas stream (e.g.,through an evaporation process). In certain embodiments, the humidifiercomprises a vessel (e.g., a stainless steel tank, a fiber-reinforcedplastic tank, or other vessel). The humidifier vessel can comprise aliquid inlet configured to receive a liquid feed stream comprising waterand at least one dissolved salt and a gas inlet configured to receive acarrier gas stream. In some embodiments, the humidifier can furthercomprise a liquid outlet and a gas outlet.

The dehumidifier may have any configuration that allows for the transferof water from a humidified gas stream to a stream comprisingsubstantially pure water (e.g., through a condensation process). Incertain embodiments, the dehumidifier comprises a vessel (e.g., astainless steel tank or other vessel). The dehumidifier vessel cancomprise a liquid inlet configured to receive a stream comprisingsubstantially pure water and a gas inlet configured to receive thehumidified gas stream. In some embodiments, the dehumidifier can furthercomprise a liquid outlet for the stream comprising substantially purewater and a gas outlet for the dehumidified gas stream.

According to some embodiments, the humidifier is a bubble columnhumidifier (e.g., a humidifier in which the evaporation process occursthrough direct contact between a liquid feed stream and bubbles of acarrier gas) and/or the dehumidifier is a bubble column dehumidifier(e.g., a dehumidifier in which the condensation process occurs throughdirect contact between a substantially pure liquid stream and bubbles ofa humidified gas). In some cases, bubble column humidifiers and bubblecolumn dehumidifiers may be associated with certain advantages. Forexample, bubble column humidifiers and dehumidifiers may exhibit higherthermodynamic effectiveness than certain other types of humidifiers(e.g., packed bed humidifiers, spray towers, wetted wall towers) anddehumidifiers (e.g., surface condensers). Without wishing to be bound bya particular theory, the increased thermodynamic effectiveness may be atleast partially attributed to the use of gas bubbles for heat and masstransfer in bubble column humidifiers and dehumidifiers, since gasbubbles may have more surface area available for heat and mass transferthan many other types of surfaces (e.g., metallic tubes, liquid films,packing material). In addition, bubble column humidifiers anddehumidifiers may have certain features that further increasethermodynamic effectiveness, including, but not limited to, relativelylow liquid level height, relatively high aspect ratio liquid flow paths,and multi-staged designs.

In certain embodiments, a bubble column humidifier comprises at leastone stage comprising a chamber and a liquid layer positioned within aportion of the chamber. The liquid layer may, in some cases, comprise aliquid comprising water and at least one dissolved salt. The chamber mayfurther comprise a gas distribution region occupying at least a portionof the chamber not occupied by the liquid layer. In addition, thechamber may be in fluid communication with a bubble generator (e.g., asparger plate). In some embodiments, a carrier gas stream flows throughthe bubble generator, forming bubbles of the carrier gas. The carriergas bubbles may then travel through the liquid layer. The liquid layermay be maintained at a temperature higher than the temperature of thegas bubbles, and as the gas bubbles directly contact the liquid layer,heat and/or mass may be transferred from the liquid layer to the gasbubbles. In some cases, at least a portion of water may be transferredto the gas bubbles through an evaporation process. The bubbles of thehumidified gas may exit the liquid layer and enter the gas distributionregion. The humidified gas may be substantially homogeneouslydistributed throughout the gas distribution region. The humidified gasmay then exit the bubble column humidifier as a humidified gas stream.

In some embodiments, a bubble column dehumidifier comprises at least onestage comprising a chamber and a liquid layer positioned within aportion of the chamber. The liquid layer may, in some cases, comprisesubstantially pure water. The chamber may further comprise a gasdistribution region occupying at least a portion of the chamber notoccupied by the liquid layer. In addition, the chamber may be in fluidcommunication with a bubble generator (e.g., a sparger plate). In someembodiments, the humidified gas stream flows from the humidifier throughthe bubble generator, forming bubbles of the humidified gas. The bubblesof the humidified gas may then travel through the liquid layer. Theliquid layer may be maintained at a temperature lower than thetemperature of the humidified gas bubbles, and as the humidified gasbubbles directly contact the liquid layer, heat and/or mass may betransferred from the humidified gas bubbles to the liquid layer via acondensation process.

Suitable bubble column condensers that may be used as the dehumidifierin certain systems and methods described herein include those describedin U.S. Pat. No. 8,523,985, by Govindan et al., issued Sep. 3, 2013, andentitled “Bubble-Column Vapor Mixture Condenser”; U.S. Pat. No.8,778,065, by Govindan et al., issued Jul. 15, 2014, and entitled“Humidification-Dehumidification System Including a Bubble-Column VaporMixture Condenser”; U.S. Patent Publication No. 2013/0074694, byGovindan et al., filed on Sep. 23, 2011, and entitled “Bubble-ColumnVapor Mixture Condenser”; U.S. Patent Publication No. 2015/0129410,filed on Sep. 12, 2014, and entitled “Systems Including a CondensingApparatus such as a Bubble Column Condenser”; U.S. patent applicationSer. No. 14/538,619, filed on Nov. 11, 2014, and entitled “SystemsIncluding a Condensing Apparatus such as a Bubble Column Condenser”;U.S. Provisional Patent Application No. 61/877,032, filed on Sep. 12,2013, and entitled “Systems Including a Bubble Column Condenser”; andU.S. Provisional Patent Application No. 61/881,365, filed on Sep. 23,2013, and entitled “Desalination Systems and Associated Methods,” eachof which is incorporated herein by reference in its entirety for allpurposes. Suitable bubble column humidifiers that may be used as thehumidifier in certain systems and methods described herein include thosedescribed in International Patent Publication No. WO 2014/00829, byGovindan et al., filed Jun. 6, 2014, as International Patent ApplicationNo. PCT/US2014/41226, and entitled “Multi-Stage Bubble ColumnHumidifier,” which is incorporated herein by reference in its entiretyfor all purposes.

In some embodiments, the humidifier and/or dehumidifier comprise aplurality of stages. For example, the stages may be arranged such that agas (e.g., a carrier gas, a humidified gas) flows sequentially from afirst stage to a second stage. In some cases, the stages may be arrangedin a vertical fashion (e.g., a second stage positioned above a firststage) or a horizontal fashion (e.g., a second stage positioned to theright or left of a first stage). In some cases, each stage may comprisea liquid layer. In embodiments relating to a humidifier comprising aplurality of stages (e.g., a multi-stage humidifier), the temperature ofthe liquid layer of the first stage (e.g., the bottommost stage in avertically arranged bubble column) may be lower than the temperature ofthe liquid layer of the second stage, which may be lower than thetemperature of the liquid layer of the third stage (e.g., the topmoststage in a vertically arranged bubble column). In embodiments relatingto a dehumidifier comprising a plurality of stages (e.g., a multi-stagedehumidifier), the temperature of the liquid layer of the first stagemay be higher than the temperature of the liquid layer of the secondstage, which may be higher than the temperature of the liquid layer ofthe third stage.

The presence of multiple stages within a bubble column humidifier and/orbubble column dehumidifier may, in some cases, advantageously result inincreased humidification and/or dehumidification of a gas. In somecases, the presence of multiple stages may advantageously lead to higherrecovery of substantially pure water. For example, the presence ofmultiple stages may provide numerous locations where the gas may behumidified and/or dehumidified (e.g., treated to recover substantiallypure water). That is, the gas may travel through more than one liquidlayer in which at least a portion of the gas undergoes humidification(e.g., evaporation) or dehumidification (e.g., condensation). Inaddition, the presence of multiple stages may increase the difference intemperature between a liquid stream at an inlet and an outlet of ahumidifier and/or dehumidifier. This may be advantageous in systemswhere heat from a liquid stream (e.g., dehumidifier liquid outletstream) is transferred to a separate stream (e.g., humidifier inputstream) within the system. In such cases, the ability to produce aheated dehumidifier liquid outlet stream can increase the energyeffectiveness of the system. Additionally, the presence of multiplestages may enable greater flexibility for fluid flow within anapparatus. For example, extraction and/or injection of fluids (e.g., gasstreams) from intermediate humidification and/or dehumidification stagesmay occur through intermediate exchange conduits.

In some cases, a bubble column humidifier and/or a bubble columndehumidifier is configured to extract partially humidified gas from atleast one intermediate location in the humidifier (e.g., not the finalhumidification stage) and to inject the partially humidified gas into atleast one intermediate location in the dehumidifier (e.g., not the firstdehumidification stage). In some embodiments, extraction from at leastone intermediate location in the humidifier and injection into at leastone intermediate location in the dehumidifier may be thermodynamicallyadvantageous. Because the portion of the gas flow exiting the humidifierat an intermediate outlet (e.g., the extracted portion) has not passedthrough the entire humidifier, the temperature of the gas flow at theintermediate outlet may be lower than the temperature of the gas flow atthe main gas outlet of the humidifier. The location of the extractionpoints (e.g., outlets) and/or injection points (e.g., inlets) may beselected to increase the thermal efficiency of the system. For example,because a gas (e.g., air) may have increased vapor content at highertemperatures than at lower temperatures, and because the heat capacityof a gas with higher vapor content may be higher than the heat capacityof a gas with lower vapor content, less gas may be used in highertemperature areas of the humidifier and/or dehumidifier to betterbalance the heat capacity rate ratios of the gas (e.g., air) and liquid(e.g., water) streams. Extraction and/or injection at intermediatelocations may therefore advantageously allow for manipulation of gasmass flows and for greater heat recovery.

The humidifier and/or dehumidifier may be of any size. In some cases,the size of the humidifier and/or dehumidifier will generally dependupon the number of humidifier units and/or dehumidifier units employedin the system and the total flow rate of the liquid that is to bedesalinated. In certain embodiments, the total of the volumes of thehumidifiers used in the desalination system can be at least about 1gallon, at least about 10 gallons, at least about 100 gallons, at leastabout 500 gallons, at least about 1,000 gallons, at least about 2,000gallons, at least about 5,000 gallons, at least about 7,000 gallons, atleast about 10,000 gallons, at least about 20,000 gallons, at leastabout 50,000 gallons, or at least about 100,000 gallons (and/or, in someembodiments, up to about 1,000,000 gallons, or more).

In some embodiments, the desalination system may have a relatively highliquid feed rate (e.g., amount of liquid feed entering the system perunit time). In certain embodiments, the desalination system has a liquidfeed rate of at least about 5 barrels/day, at least about 10barrels/day, at least about 20 barrels/day, at least about 50barrels/day, at least about 100 barrels/day, at least about 200barrels/day, at least about 300 barrels/day, at least about 400barrels/day, at least about 500 barrels/day, at least about 600barrels/day, at least about 700 barrels/day, at least about 800barrels/day, at least about 900 barrels/day, at least about 1,000barrels a day, at least about 2,000 barrels/day, at least about 5,000barrels/day, at least about 10,000 barrels/day, at least about 20,000barrels/day, at least about 30,000 barrels/day, at least about 35,000barrels/day, at least about 50,000 barrels/day (and/or, in someembodiments, up to about 100,000 barrels/day, or more).

In some embodiments, the desalination system may have a relatively highproduction rate (e.g., amount of substantially pure water produced perunit time). In certain cases, the desalination system has a productionrate of at least about 10 barrels/day, at least about 50 barrels/day, atleast about 100 barrels/day, at least about 200 barrels/day, at leastabout 300 barrels/day, at least about 400 barrels/day, at least about500 barrels/day, at least about 600 barrels/day, at least about 700barrels/day, at least about 800 barrels/day, at least about 900barrels/day, at least about 1,000 barrels a day, at least about 2,000barrels/day, at least about 5,000 barrels/day, or at least about 10,000barrels/day (and/or, in some embodiments, up to about 100,000barrels/day, or more).

It should be recognized that other types of humidifiers and/ordehumidifiers may be used in systems and methods described herein. Forexample, in some embodiments, the humidifier is a packed bed humidifier.In certain cases, the humidifier comprises a packing material (e.g.,polyvinyl chloride (PVC) packing material). The packing material may, insome cases, facilitate turbulent gas flow and/or enhanced direct contactbetween the liquid stream comprising water and at least one dissolvedsalt and the carrier gas stream within the humidifier. In certainembodiments, the humidifier further comprises a device configured toproduce droplets of the liquid feed stream. For example, a nozzle orother spraying device may be positioned at the top of the humidifiersuch that the liquid feed stream is sprayed downward to the bottom ofthe humidifier. The use of a spraying device can advantageously increasethe degree of contact between the liquid feed stream fed to thehumidifier and the carrier gas stream into which water from the liquidfeed stream is transported.

In some embodiments, the desalination system further comprises one ormore additional devices. According to some embodiments, for example, thedesalination system further comprises a heat exchanger in fluidcommunication with the humidifier and/or dehumidifier. In certain cases,the heat exchanger advantageously facilitates transfer of heat from aliquid stream exiting the dehumidifier to a liquid stream entering thehumidifier. For example, the heat exchanger may advantageously allowenergy to be recovered from a dehumidifier liquid outlet stream and usedto pre-heat a humidifier liquid inlet stream prior to entry of thehumidifier liquid inlet stream into the humidifier.

In certain embodiments, the desalination system further comprises anoptional heating device arranged in fluid communication with thehumidifier. The optional heating device may be any device capable oftransferring heat to a liquid stream. The heating device may be a heatexchanger, a heat collection device (e.g., a device configured to storeand/or utilize thermal energy), or an electric heater. In certain cases,the heating device may be arranged such that a liquid feed stream isheated prior to entering the humidifier. Heating the liquid feed streammay, in some cases, increase the degree to which water is transferredfrom the liquid feed stream to the carrier gas stream within thehumidifier.

In some embodiments, the desalination system further comprises anoptional cooling device arranged in fluid communication with thedehumidifier. In certain cases, a stream comprising substantially purewater may be cooled by the cooling device prior to entering thedehumidifier. A cooling device generally refers to any device that iscapable of removing heat from a fluid stream (e.g., a liquid stream, agas stream). The cooling device may be a heat exchanger (e.g., anair-cooled heat exchanger), a dry cooler, a chiller, a radiator, or anyother device capable of removing heat from a fluid stream.

It should be understood that the inventive systems and methods describedherein are not limited to those including ahumidification-dehumidification desalination system, and that in otherembodiments, other desalination system types may be employed.Non-limiting examples of suitable desalination systems include amechanical vapor compression system, a multi-effect distillation system,a multi-stage flash system, and/or a vacuum distillation system. In someembodiments, the desalination system is a hybrid desalination systemcomprising a first desalination unit and a second desalination unit,each of which may be any type of desalination system. The firstdesalination unit and second desalination unit may be the same ordifferent types of desalination systems.

Certain of the systems described herein can be configured to desalinatesaline solutions entering at relatively high flow rates, and,accordingly, can be configured to produce relative pure water streams atrelatively high flow rates. For example, in some embodiments, thesystems and methods described herein may be configured and sized tooperate to receive an aqueous feed stream at a flow rate of at leastabout 1 gallon/minute, at least about 10 gallons/minute, at least about100 gallons/minute, or at least about 1000 gallons/minute (and/or, incertain embodiments, up to about 10,000 gallons/minute, or more).

In some embodiments, the dehumidifier is configured to produce a streamcomprising water of relatively high purity (e.g., a substantially purewater stream). For example, in some embodiments, the dehumidifierproduces a stream comprising water in an amount of at least about 95 wt%, at least about 99 wt %, at least about 99.9 wt %, or at least about99.99 wt % (and/or, in certain embodiments, up to about 99.999 wt %, ormore). In some embodiments, the percentage volume of a liquid feedstream that is recovered as fresh water is at least about 40%, at leastabout 45%, at least about 50%, at least about 55%, at least about 58%,at least about 60%, or at least about 70%.

In some embodiments, the substantially pure water stream has arelatively low concentration of one or more dissolved salts. In somecases, the concentration of at least one dissolved salt in thesubstantially pure water stream is about 500 mg/L or less, about 200mg/L or less, about 100 mg/L or less, about 50 mg/L or less, about 20mg/L or less, about 10 mg/L or less, about 5 mg/L or less, about 2 mg/Lor less, about 1 mg/L or less, about 0.5 mg/L or less, about 0.2 mg/L orless, about 0.1 mg/L or less, or about 0.01 mg/L or less. According tosome embodiments, the concentration of at least one dissolved salt inthe substantially pure water stream may be substantially zero (e.g., notdetectable). In certain cases, the concentration of at least onedissolved salt in the substantially pure water stream is in the range ofabout 0.01 mg/L to about 500 mg/L, about 0.01 mg/L to about 200 mg/L,about 0.01 mg/L to about 100 mg/L, about 0.01 mg/L to about 50 mg/L,about 0.01 mg/L to about 20 mg/L, about 0.01 mg/L to about 10 mg/L,about 0.01 mg/L to about 5 mg/L, about 0.01 mg/L to about 2 mg/L, about0.01 mg/L to about 1 mg/L, about 0 mg/L to about 500 mg/L, about 0 mg/Lto about 200 mg/L, about 0 mg/L to about 100 mg/L, about 0 mg/L to about50 mg/L, about 0 mg/L to about 20 mg/L, about 0 mg/L to about 10 mg/L,about 0 mg/L to about 5 mg/L, about 0 mg/L to about 2 mg/L, about 0 mg/Lto about 1 mg/L, about 0 mg/L to about 0.1 mg/L, or about 0 mg/L toabout 0.01 mg/L. The concentration of a dissolved salt may be measuredaccording to any method known in the art. For example, suitable methodsfor measuring the concentration of a dissolved salt include inductivelycoupled plasma (ICP) spectroscopy (e.g., inductively coupled plasmaoptical emission spectroscopy). As one non-limiting example, an Optima8300 ICP-OES spectrometer may be used.

In some embodiments, the substantially pure water stream contains atleast one dissolved salt in an amount of about 2 wt % or less, about 1wt % or less, about 0.5 wt % or less, about 0.2 wt % or less, about 0.1wt % or less, about 0.05 wt % or less, or about 0.01 wt % or less. Insome embodiments, the substantially pure water stream contains at leastone dissolved salt in an amount in the range of about 0.01 wt % to about2 wt %, about 0.01 wt % to about 1 wt %, about 0.01 wt % to about 0.5 wt%, about 0.01 wt % to about 0.2 wt %, or about 0.01 wt % to about 0.1 wt%.

In some embodiments, the substantially pure water stream has arelatively low total dissolved salt concentration. In some cases, thetotal dissolved salt concentration in the substantially pure waterstream is about 500 mg/L or less, about 200 mg/L or less, about 100 mg/Lor less, about 50 mg/L or less, about 20 mg/L or less, about 10 mg/L orless, about 5 mg/L or less, about 2 mg/L or less, about 1 mg/L or less,about 0.5 mg/L or less, about 0.1 mg/L or less, or about 0.01 mg/L orless. According to some embodiments, the total dissolved saltconcentration in the substantially pure water stream may besubstantially zero (e.g., not detectable). In certain embodiments, thetotal dissolved salt concentration in the substantially pure waterstream is in the range of about 0.01 mg/L to about 500 mg/L, about 0.01mg/L to about 200 mg/L, about 0.01 mg/L to about 100 mg/L, about 0.01mg/L to about 50 mg/L, about 0.01 mg/L to about 20 mg/L, about 0.01 mg/Lto about 10 mg/L, about 0.01 mg/L to about 5 mg/L, about 0.01 mg/L toabout 2 mg/L, about 0.01 mg/L to about 1 mg/L, about 0 mg/L to about 500mg/L, about 0 mg/L to about 200 mg/L, about 0 mg/L to about 100 mg/L,about 0 mg/L to about 50 mg/L, about 0 mg/L to about 20 mg/L, about 0mg/L to about 10 mg/L, about 0 mg/L to about 5 mg/L, about 0 mg/L toabout 2 mg/L, about 0 mg/L to about 1 mg/L, about 0 mg/L to about 0.1mg/L, or about 0 mg/L to about 0.01 mg/L. Total dissolved saltconcentration may be measured according to any method known in the art.For example, a non-limiting example of a suitable method for measuringtotal dissolved salt concentration is the SM 2540C method. According tothe SM 2540C method, a sample comprising an amount of liquid comprisingone or more dissolved solids is filtered (e.g., through a glass fiberfilter), and the filtrate is evaporated to dryness in a weighed dish at180° C. The increase in dish weight represents the mass of the totaldissolved solids in the sample. The total dissolved salt concentrationof the sample may be obtained by dividing the mass of the totaldissolved solids by the volume of the original sample.

In some embodiments, the total dissolved salt concentration of thesubstantially pure water stream is substantially less than the totaldissolved salt concentration of an aqueous feed stream received by thedesalination system. In some cases, the total dissolved saltconcentration of the substantially pure water stream is at least about0.5%, about 1%, about 2%, about 5%, about 10%, about 15%, or about 20%less than the total dissolved salt concentration of the aqueous feedstream.

According to some embodiments, the substantially pure water stream has arelatively low salinity (e.g., weight percent of all dissolved salts).In some embodiments, the substantially pure water stream has a salinityof about 5% or less, about 2% or less, about 1% or less, about 0.5% orless, about 0.2% or less, about 0.1% or less, about 0.05% or less, orabout 0.01% or less. In some embodiments, the substantially pure waterstream has a salinity in the range of about 0.01% to about 5%, about0.01% to about 2%, about 0.01% to about 1%, about 0.01% to about 0.5%,about 0.01% to about 0.2%, or about 0.01% to about 0.1%. Salinity may bemeasured according to any method known in the art. For example, anon-limiting example of a suitable method for measuring salinity is theSM 2540C method. According to the SM 2540C method, a sample comprisingan amount of liquid comprising one or more dissolved solids is filtered(e.g., through a glass fiber filter), and the filtrate is evaporated todryness in a weighed dish at 180° C. The increase in dish weightrepresents the mass of the total dissolved solids in the sample. Thesalinity of the sample may be obtained by dividing the mass of the totaldissolved solids by the mass of the original sample and multiplying theresultant number by 100.

According to some embodiments, the humidifier is configured to produce aconcentrated brine stream (e.g., a stream comprising a relatively highconcentration of at least one dissolved salt). The concentrated brinestream may, in some cases, have a relatively high salinity. In somecases, the salinity of the concentrated brine stream is at least about10%, at least about 15%, at least about 20%, at least about 25%, atleast about 26%, at least about 27%, at least about 28%, at least about29%, or at least about 30%. In some embodiments, the salinity of theconcentrated brine stream is in the range of about 10% to about 20%,about 10% to about 25%, about 10% to about 26%, about 10% to about 27%,about 10% to about 28%, about 10% to about 29%, about 10% to about 30%,about 15% to about 20%, about 15% to about 25%, about 15% to about 26%,about 15% to about 27%, about 15% to about 28%, about 15% to about 29%,about 15% to about 30%, about 20% to about 25%, about 20% to about 26%,about 20% to about 27%, about 20% to about 28%, about 20% to about 29%,about 20% to about 30%, about 25 wt % to about 26 wt %, about 25 wt % toabout 27 wt %, about 25 wt % to about 28 wt %, about 25 wt % to about 29wt %, or about 25% to about 30%.

The concentrated brine stream may, in some cases, have a relatively highconcentration of at least one dissolved salt (e.g., NaCl). In certaincases, the concentration of at least one dissolved salt in theconcentrated brine stream is at least about 100 mg/L, at least about 200mg/L, at least about 400 mg/L, at least about 500 mg/L, at least about800 mg/L, at least about 1,000 mg/L, at least about 2,000 mg/L, at leastabout 4,000 mg/L, at least about 5,000 mg/L, at least about 8,000 mg/L,at least about 10,000 mg/L, at least about 20,000 mg/L, at least about40,000 mg/L, at least about 45,000 mg/L, at least about 50,000 mg/L, atleast about 80,000 mg/L, at least about 100,000 mg/L, at least about150,000 mg/L, at least about 200,000 mg/L, at least about 250,000 mg/L,at least about 300,000 mg/L, at least about 350,000 mg/L, at least about400,000 mg/L, at least about 450,000 mg/L, or at least about 500,000mg/L (and/or, in certain embodiments, up to the solubility limit of thesalt in the concentrated brine stream). In some embodiments, theconcentration of at least one dissolved salt in the concentrated brinestream is in the range of about 10,000 mg/L to about 20,000 mg/L, about10,000 mg/L to about 40,000 mg/L, about 10,000 mg/L to about 45,000mg/L, about 10,000 mg/L to about 50,000 mg/L, about 10,000 mg/L to about80,000 mg/L, about 10,000 mg/L to about 100,000 mg/L, about 10,000 mg/Lto about 150,000 mg/L, about 10,000 mg/L to about 200,000 mg/L, about10,000 mg/L to about 250,000 mg/L, about 10,000 mg/L to about 300,000mg/L, about 10,000 mg/L to about 350,000 mg/L, about 10,000 mg/L toabout 400,000 mg/L, about 10,000 mg/L to about 450,000 mg/L, about10,000 mg/L to about 500,000 mg/L about 20,000 mg/L to about 50,000mg/L, about 20,000 mg/L to about 80,000 mg/L, about 20,000 mg/L to about100,000 mg/L, about 20,000 mg/L to about 150,000 mg/L, about 20,000 mg/Lto about 200,000 mg/L, about 20,000 mg/L to about 250,000 mg/L, about20,000 mg/L to about 300,000 mg/L, about 20,000 mg/L to about 350,000mg/L, about 20,000 mg/L to about 400,000 mg/L, about 20,000 mg/L toabout 450,000 mg/L, about 20,000 mg/L to about 500,000 mg/L about 50,000mg/L to about 100,000 mg/L, about 50,000 mg/L to about 150,000 mg/L,about 50,000 mg/L to about 200,000 mg/L, about 50,000 mg/L to about250,000 mg/L, about 50,000 mg/L to about 300,000 mg/L, about 50,000 mg/Lto about 350,000 mg/L, about 50,000 mg/L to about 400,000 mg/L, about50,000 mg/L to about 450,000 mg/L, about 50,000 to about 500,000 mg/L,about 100,000 mg/L to about 150,000 mg/L, about 100,000 mg/L to about200,000 mg/L, about 100,000 mg/L to about 250,000 mg/L, about 100,000mg/L to about 300,000 mg/L, about 100,000 mg/L to about 350,000 mg/L,about 100,000 mg/L to about 400,000 mg/L, about 100,000 mg/L to about450,000 mg/L, or about 100,000 mg/L to about 500,000 mg/L.

In some embodiments, the concentrated brine stream contains at least onedissolved salt (e.g., NaCl) in an amount of at least about 1 wt %, atleast about 5 wt %, at least about 10 wt %, at least about 15 wt %, atleast about 20 wt %, at least about 25 wt %, at least about 26 wt %, atleast about 27 wt %, at least about 28 wt %, at least about 29 wt %, orat least about 30 wt % (and/or, in certain embodiments, up to thesolubility limit of the salt in the concentrated brine stream). In someembodiments, the concentrated brine stream comprises at least onedissolved salt in an amount in the range of about 1 wt % to about 10 wt%, about 1 wt % to about 20 wt %, about 1 wt % to about 25 wt %, about 1wt % to about 26 wt %, about 1 wt % to about 27 wt %, about 1 wt % toabout 28 wt %, about 1 wt % to about 29 wt %, about 1 wt % to about 30wt %, about 10 wt % to about 20 wt %, about 10 wt % to about 25 wt %,about 10 wt % to about 26 wt %, about 10 wt % to about 27 wt %, about 10wt % to about 28 wt %, about 10 wt % to about 29 wt %, about 10 wt % toabout 30 wt %, about 20 wt % to about 25 wt %, about 20 wt % to about 26wt %, about 20 wt % to about 27 wt %, about 20 wt % to about 28 wt %,about 20 wt % to about 29 wt %, about 20 wt % to about 30 wt %, about 25wt % to about 26 wt %, about 25 wt % to about 27 wt %, about 25 wt % toabout 28 wt %, about 25 wt % to about 29 wt %, or about 25 wt % to about30 wt %.

In some embodiments, the total dissolved salt concentration of theconcentrated brine stream may be relatively high. In certain cases, thetotal dissolved salt concentration of the concentrated brine stream isat least about 100 mg/L, at least about 200 mg/L, at least about 500mg/L, at least about 1,000 mg/L, at least about 2,000 mg/L, at leastabout 5,000 mg/L, at least about 10,000 mg/L, at least about 20,000mg/L, at least about 50,000 mg/L, at least about 75,000 mg/L, at leastabout 100,000 mg/L, at least about 150,000 mg/L, at least about 200,000mg/L, at least about 250,000 mg/L, at least about 300,000 mg/L, at leastabout 350,000 mg/L, at least about 400,000 mg/L, at least about 450,000mg/L, at least about 500,000 mg/L, at least about 550,000 mg/L, or atleast about 600,000 mg/L (and/or, in certain embodiments, up to thesolubility limit of the salt(s) in the concentrated brine stream). Insome embodiments, the total dissolved salt concentration of theconcentrated brine stream is in the range of about 10,000 mg/L to about20,000 mg/L, about 10,000 mg/L to about 50,000 mg/L, about 10,000 mg/Lto about 100,000 mg/L, about 10,000 mg/L to about 150,000 mg/L, about10,000 mg/L to about 200,000 mg/L, about 10,000 mg/L to about 250,000mg/L, about 10,000 mg/L to about 300,000 mg/L, about 10,000 mg/L toabout 350,000 mg/L, or about 10,000 mg/L to about 400,000 mg/L, about10,000 mg/L to about 450,000 mg/L, about 10,000 mg/L to about 500,000mg/L, about 10,000 mg/L to about 550,000 mg/L, about 10,000 mg/L toabout 600,000 mg/L, about 20,000 mg/L to about 50,000 mg/L, about 20,000mg/L to about 100,000 mg/L, about 20,000 mg/L to about 150,000 mg/L,about 20,000 mg/L to about 200,000 mg/L, about 20,000 mg/L to about250,000 mg/L, about 20,000 mg/L to about 300,000 mg/L, about 20,000 mg/Lto about 350,000 mg/L, about 20,000 mg/L to about 400,000 mg/L, about20,000 mg/L to about 450,000 mg/L, about 20,000 mg/L to about 500,000mg/L, about 20,000 mg/L to about 550,000 mg/L, about 20,000 mg/L toabout 600,000 mg/L, about 50,000 mg/L to about 100,000 mg/L, about50,000 mg/L to about 150,000 mg/L, about 50,000 mg/L to about 200,000mg/L, about 50,000 mg/L to about 250,000 mg/L, about 50,000 mg/L toabout 300,000 mg/L, about 50,000 mg/L to about 350,000 mg/L, about50,000 mg/L to about 400,000 mg/L, about 50,000 mg/L to about 450,000mg/L, about 50,000 mg/L to about 500,000 mg/L, about 50,000 mg/L toabout 550,000 mg/L, about 50,000 mg/L to about 600,000 mg/L, about100,000 mg/L to about 200,000 mg/L, about 100,000 mg/L to about 250,000mg/L, about 100,000 mg/L to about 300,000 mg/L, about 100,000 mg/L toabout 350,000 mg/L, about 100,000 mg/L to about 400,000 mg/L, about100,000 mg/L to about 450,000 mg/L, about 100,000 mg/L to about 500,000mg/L, about 100,000 mg/L to about 550,000 mg/L, or about 100,000 mg/L toabout 600,000 mg/L.

In some embodiments, the concentrated brine stream contains a totalamount of dissolved salts of at least about 1 wt %, at least about 5 wt%, at least about 10 wt %, at least about 15 wt %, at least about 20 wt%, at least about 25 wt %, at least about 26 wt %, at least about 27 wt%, at least about 28 wt %, at least about 29 wt %, or at least about 30wt %. In some embodiments, the concentrated brine stream comprises atotal amount of dissolved salts in the range of about 1 wt % to about 10wt %, about 1 wt % to about 20 wt %, about 1 wt % to about 25 wt %,about 1 wt % to about 26 wt %, about 1 wt % to about 27 wt %, about 1 wt% to about 28 wt %, about 1 wt % to about 29 wt %, about 1 wt % to about30 wt %, about 10 wt % to about 20 wt %, about 10 wt % to about 25 wt %,about 10 wt % to about 26 wt %, about 10 wt % to about 27 wt %, about 10wt % to about 28 wt %, about 10 wt % to about 29 wt %, about 10 wt % toabout 30 wt %, about 20 wt % to about 25 wt %, about 20 wt % to about 26wt %, about 20 wt % to about 27 wt %, about 20 wt % to about 28 wt %,about 20 wt % to about 29 wt %, about 20 wt % to about 30 wt %, about 25wt % to about 26 wt %, about 25 wt % to about 27 wt %, about 25 wt % toabout 28 wt %, about 25 wt % to about 29 wt %, or about 25 wt % to about30 wt %.

In some embodiments, the total dissolved salt concentration of theconcentrated brine stream is significantly higher than the totaldissolved salt concentration of an aqueous feed stream received by thedesalination system. In some cases, the total dissolved saltconcentration of the concentrated brine stream is at least about 5%, atleast about 6%, at least about 10%, at least about 14%, at least about15%, at least about 20%, or at least about 25% greater than the totaldissolved salt concentration of the aqueous feed stream.

According to some embodiments, one or more additional salts may be addedto the concentrated brine stream to produce an ultra-high-densityconcentrated brine stream. Non-limiting examples of suitable salts toadd to a concentrated brine stream to produce an ultra-high-densityconcentrated brine stream include sodium chloride (NaCl), calciumchloride (CaCl₂), magnesium chloride (MgCl₂), copper (II) chloride(CuCl₂), iron (III) chloride hexahydrate (FeCl₃.6H₂O), iron (III)chloride (FeCl₃), lithium chloride (LiCl), manganese (II) chloride(MnCl₂), nickel (II) chloride (NiCl₂), zinc chloride (ZnCl₂), sodiumbromide (NaBr), calcium bromide (CaBr₂), magnesium bromide (MgBr₂),potassium bromide (KBr), copper (II) bromide (CuBr₂), iron (III) bromide(FeBr₃), lithium bromide (LiBr), manganese (II) bromide (MnBr₂), nickel(II) bromide (NiBr₂), zinc bromide (ZnBr₂), ammonium nitrate (NH₄NO₃),sodium nitrate (NaNO₃), lithium nitrate (LiNO₃), calcium nitrate(Ca(NO₃)₂), magnesium nitrate (Mg(NO₃)₂), strontium nitrate (Sr(NO₃)₂),calcium nitrate tetrahydrate (Ca(NO₃)₂.4H₂O), copper (II) nitrate(Cu(NO₃)₂), iron (II) nitrate (Fe(NO₃)₂), iron (III) nitrate (Fe(NO₃)₃),nickel (II) nitrate (Ni(NO₃)₂), and/or zinc nitrate (Zn(NO₃)₂). In someembodiments, at least one of the one or more additional salts added to aconcentrated brine stream comprising water and at least one dissolvedsalt is different from the at least one dissolved salt. In someembodiments, each of the one or more additional salts added to theconcentrated brine stream is different from the at least one dissolvedsalt. In certain cases, at least one of the one or more additional saltsadded to the concentrated brine stream is the same as the at least onedissolved salt.

In some embodiments, the ultra-high-density concentrated brine streamhas a density (e.g., measured at about 60° F.) of at least about 11.7pounds/gallon, at least about 12 pounds/gallon, at least about 12.5pounds/gallon, at least about 13 pounds/gallon, at least about 13.2pounds/gallon, at least about 13.5 pounds/gallon, at least about 14pounds/gallon, at least about 14.5 pounds/gallon, at least about 15pounds/gallon, at least about 20 pounds/gallon, or at least about 25pounds/gallon. In certain cases, the ultra-high-density concentratedbrine stream has a density (e.g., measured at about 60° F.) in the rangeof about 11.7 pounds/gallon to about 12.5 pounds/gallon, about 11.7pounds/gallon to about 13 pounds/gallon, about 11.7 pounds/gallon toabout 13.2 pounds/gallon, about 11.7 pounds/gallon to about 13.5pounds/gallon, about 11.7 pounds/gallon to about 14 pounds/gallon, about11.7 pounds/gallon to about 14.5 pounds/gallon, about 11.7 pounds/gallonto about 15 pounds/gallon, about 11.7 pounds/gallon to about 20pounds/gallon, about 11.7 pounds/gallon to about 25 pounds/gallon, about12 pounds/gallon to about 12.5 pounds/gallon, about 12 pounds/gallon toabout 13 pounds/gallon, about 12 pounds/gallon to about 13.2pounds/gallon, about 12 pounds/gallon to about 13.5 pounds/gallon, about12 pounds/gallon to about 14 pounds/gallon, about 12 pounds/gallon toabout 14.5 pounds/gallon, about 12 pounds/gallon to about 15pounds/gallon, about 12 pounds/gallon to about 20 pounds/gallon, about12 pounds/gallon to about 25 pounds/gallon, about 12.5 pounds/gallon toabout 13 pounds/gallon, about 12.5 pounds/gallon to about 13.2pounds/gallon, about 12.5 pounds/gallon to about 13.5 pounds/gallon,about 12.5 pounds/gallon to about 14 pounds/gallon, about 12.5pounds/gallon to about 14.5 pounds/gallon, about 12.5 pounds/gallon toabout 15 pounds/gallon, about 12.5 pounds/gallon to about 20pounds/gallon, about 12.5 pounds/gallon to about 25 pounds/gallon, about13 pounds/gallon to about 13.2 pounds/gallon, about 13 pounds/gallon toabout 13.5 pounds/gallon, about 13 pounds/gallon to about 14pounds/gallon, about 13 pounds/gallon to about 14.5 pounds/gallon, about13 pounds/gallon to about 15 pounds/gallon, about 13 pounds/gallon toabout 20 pounds/gallon, about 13 pounds/gallon to about 25pounds/gallon, about 13.5 pounds/gallon to about 14 pounds/gallon, about13.5 pounds/gallon to about 14.5 pounds/gallon, about 13.5 pounds/gallonto about 15 pounds/gallon, about 13.5 pounds/gallon to about 20pounds/gallon, about 13.5 pounds/gallon to about 25 pounds/gallon, about14 pounds/gallon to about 15 pounds/gallon, about 14 pounds/gallon toabout 20 pounds/gallon, about 14 pounds/gallon to about 25pounds/gallon, about 15 pounds/gallon to about 20 pounds/gallon, about15 pounds/gallon to about 25 pounds/gallon, or about 20 pounds/gallon toabout 25 pounds/gallon.

In some cases, the density of the ultra-high-density concentrated brinestream is measured at a temperature of about 120° F. or less, about 100°F. or less, about 80° F. or less, about 72° F. or less, about 68° F. orless, about 60° F. or less, about 50° F. or less, or about 40° F. orless. In some embodiments, the density of the ultra-high-densityconcentrated brine stream is measured at a temperature of at least about40° F., at least about 50° F., at least about 60° F., at least about 68°F., at least about 72° F., at least about 80° F., at least about 100°F., or at least about 120° F. In some embodiments, the density of theultra-high-density concentrated brine stream is measured at atemperature in the range of about 40° F. to about 120° F., about 40° F.to about 100° F., about 40° F. to about 80° F., about 40° F. to about72° F., about 40° F. to about 68° F., about 40° F. to about 60° F.,about 40° F. to about 50° F., about 60° F. to about 120° F., about 60°F. to about 100° F., about 60° F. to about 80° F., about 60° F. to about72° F., or about 60° F. to about 68° F.

In some embodiments, the water treatment system includes an optionaldisinfection unit. The disinfection unit may be, for example, achlorination system configured to add chlorine to the water. Accordingto some embodiments, the disinfection unit can be configured to receiveat least a portion of a substantially pure water stream produced by thedesalination system.

In some embodiments, the water treatment system comprises an optionalprecipitation apparatus. The precipitation apparatus may be, in certainembodiments, fluidically connected to the desalination system. In somesuch embodiments, the precipitation apparatus is configured to receiveat least a portion of a concentrated brine stream output by thedesalination system.

The precipitation apparatus is, in certain embodiments, configured toprecipitate at least a portion of the dissolved salt (e.g., dissolvedmonovalent salt) from the concentrated brine stream to produce a productstream containing less of the dissolved salt relative to theconcentrated brine stream.

The precipitation apparatus can be manufactured in any suitable manner.In certain embodiments, the precipitation apparatus comprises a vessel,such as a crystallization tank. The vessel may include an inlet throughwhich at least a portion of the concentrated brine stream produced bythe desalination system is transported into the precipitation vessel.The precipitation vessel may also include at least one outlet. Forexample, the precipitation vessel may include an outlet through whichthe substantially pure water stream (containing the dissolved salt in anamount that is less than that contained in the inlet stream) istransported. In some embodiments, the precipitation vessel includes anoutlet through which solid, precipitated salt is transported.

In some embodiments, the crystallization tank comprises a low shearmixer. The low shear mixer can be configured to keep the crystals thatare formed mixed (e.g., homogeneously mixed) in the brine stream.According to certain embodiments, the vessel is sized such that there issufficient residence time for crystals to form and grow. In certainembodiments, the precipitation apparatus comprises a vessel whichprovides at least 20 minutes of residence time for the concentratedbrine stream. As one non-limiting example, the vessel comprises,according to certain embodiments, a 6000 gallon vessel, which can beused to provide 24 minutes of residence in a 500 US barrel per day freshwater production system.

In some embodiments the crystallization tank is followed by a storagetank. The storage tank may have, in some embodiments, a capacity that issubstantially the same as the capacity of the crystallization tank. Incertain embodiments, the crystallization tank and/or the storage tankcan be configured to accommodate batch operation of the downstream solidhandling apparatus, which can be fluidically coupled to theprecipitation apparatus.

In some embodiments, the precipitation apparatus comprises at least onevessel comprising a volume within which the concentrated brine stream issubstantially quiescent. In some embodiments, the flow rate of the fluidwithin the substantially quiescent volume is less than the flow rate atwhich precipitation (e.g., crystallization) is inhibited. For example,the flow rate of the fluid within the substantially quiescent volume mayhave, in certain embodiments, a flow rate of zero. In some embodiments,the flow rate of the fluid within the substantially quiescent volume mayhave a flow rate that is sufficiently high to suspend the formed solids(e.g., crystals), but not sufficiently high to prevent solid formation(e.g., crystal nucleation). The substantially quiescent volume withinthe vessel may occupy, in some embodiments, at least about 1%, at leastabout 5%, at least about 10%, at least about 25%, at least about 50%, atleast about 75%, at least about 90%, or at least about 100% of thevolume of the vessel. As one particular example, the precipitationapparatus can comprise a vessel including a stagnation zone. Thestagnation zone may be positioned, for example, at the bottom of theprecipitation vessel. In certain embodiments, the precipitationapparatus can include a second vessel in which the solids precipitatedin the first vessel are allowed to settle. For example, an aqueousstream containing the precipitated solids can be transported to acrystallization tank, where the solids can be allowed to settle. Theremaining contents of the aqueous stream can be transported out of thecrystallization tank. While the use of two vessels within theprecipitation apparatus has been described, it should be understoodthat, in other embodiments, a single vessel, or more than two vesselsmay be employed. In certain embodiments, the desalination system can beoperated such that precipitation of the salt occurs substantially onlywithin the stagnation zone of the precipitation vessel.

In certain embodiments, the precipitation apparatus is directlyfluidically connected to the desalination system. It should beunderstood, however, that the invention is not limited to embodiments inwhich the precipitation apparatus and the desalination system aredirectly fluidically connected, and in other embodiments, theprecipitation apparatus and the desalination system are fluidicallyconnected but are not directly fluidically connected.

In some embodiments, the precipitated salt from the precipitationapparatus is fed to a solids-handling apparatus. The solids-handlingapparatus may be configured, in certain embodiments, to remove at leasta portion of the water retained by the precipitated salt. In some suchembodiments, the solids-handling apparatus is configured to produce acake comprising at least a portion of the precipitated salt from theprecipitation apparatus. As one example, the solids-handling apparatuscan comprise a filter (e.g., a vacuum drum filter or a filter press)configured to at least partially separate the precipitated salt from theremainder of a suspension containing the precipitated salt. In some suchembodiments, at least a portion of the liquid within the salt suspensioncan be transported through the filter, leaving behind solid precipitatedsalt. As one non-limiting example, a Larox FP 2016-8000 64/64 M40 PP/PPFilter (Outotec, Inc.) may be used as the filter. The filter maycomprise, in certain embodiments, a conveyor filter belt which filtersthe salt from a suspension containing the salt.

In some embodiments, the desalination system comprises a transportdevice configured to transport precipitated salt away from theprecipitation apparatus. For example, in certain embodiments, a pump isused to transport a suspension of the precipitated salt away from theprecipitation apparatus. In other embodiments, a conveyor could be usedto transport precipitated salt away from the precipitation apparatus. Incertain embodiments, the transport device is configured to transport theprecipitated salt from the precipitation apparatus to a solids-handlingapparatus.

In certain embodiments, the water treatment system is operated such thatlittle or no brine is left to be disposed from the system (alsosometimes referred to as a “zero liquid discharge” system). In some suchembodiments, the system produces a salt product and a fresh waterproduct. The salt product can be produced, for example, as a product ofa crystallization or other precipitation step.

Certain of the water treatments described herein comprise a desalinationsystem configured to remove water from an aqueous stream to produce aconcentrated brine stream enriched in a dissolved salt relative to theaqueous stream received by the desalination system. According to someembodiments, the desalination system can be configured to produce awater-containing stream that contains a lower concentration of thedissolved salt than the stream fed to the desalination system (e.g., asubstantially pure water stream).

In some embodiments, water treatment systems and methods describedherein may be used to produce two or more product streams. In someembodiments, a water treatment system may produce a first streamcomprising a first concentration of one or more contaminants. In someembodiments, the water treatment system may produce a second streamcomprising a second concentration of the one or more contaminants,wherein the second concentration is lower than the first concentration.

In some embodiments, the desalination system is separate from each ofthe separation apparatus, the suspended solids removal apparatus, theion-removal apparatus, the pH adjustment apparatus, the VOM removalapparatus, and the filtration apparatus.

In some embodiments, the desalination system is fluidically connected toone or more components of the clean brine system. In certainembodiments, the desalination system is directly fluidically connectedto one or more components of the clean brine system. The desalinationsystem may be, in some cases, upstream or downstream of one or morecomponents of the clean brine system.

In some embodiments, for example, a desalination system can befluidically connected to a separation apparatus. In certain cases, thedesalination system is directly fluidically connected to the separationapparatus. In some embodiments, the input stream received by thedesalination system comprises at least a portion of the immisciblephase-diminished stream produced by the separation apparatus. That is tosay, in certain embodiments, the desalination system is downstream ofthe separation apparatus. In other embodiments, the input streamreceived by the separation apparatus comprises at least a portion of theconcentrated brine stream and/or substantially pure water streamproduced by the desalination system. That is to say, in certainembodiments, the separation apparatus can be located downstream of thedesalination system.

In some embodiments, for example, a desalination system can befluidically connected to an ion-removal apparatus. In certain cases, thedesalination system is directly fluidically connected to the ion-removalapparatus. In some embodiments, the input stream received by thedesalination system comprises at least a portion of the ion-diminishedstream produced by the ion-removal apparatus. That is to say, in certainembodiments, the desalination system is downstream of the ion-removalapparatus. In other embodiments, the input stream received by theion-removal apparatus comprises at least a portion of the concentratedbrine stream and/or substantially pure water stream produced by thedesalination system. That is to say, in certain embodiments, theion-removal apparatus can be located downstream of the desalinationsystem.

In some embodiments, for example, a desalination system can befluidically connected to a suspended solids removal apparatus. Incertain cases, the desalination system is directly fluidically connectedto the suspended solids removal apparatus. In some embodiments, theinput stream received by the desalination system comprises at least aportion of the suspended-solids-diminished stream produced by thesuspended solids removal apparatus. That is to say, in certainembodiments, the desalination system is downstream of the suspendedsolids removal apparatus. In other embodiments, the input streamreceived by the suspended solids removal apparatus comprises at least aportion of the concentrated brine stream and/or substantially pure waterstream produced by the desalination system. That is to say, in certainembodiments, the suspended solids removal apparatus can be locateddownstream of the desalination system.

In some embodiments, for example, a desalination system can befluidically connected to a pH adjustment apparatus. In certain cases,the desalination system is directly fluidically connected to the pHadjustment apparatus. In some embodiments, the input stream received bythe desalination system comprises at least a portion of the pH-adjustedstream produced by the pH adjustment apparatus. That is to say, incertain embodiments, the desalination system is downstream of the pHadjustment apparatus. In other embodiments, the input stream received bythe pH adjustment apparatus comprises at least a portion of theconcentrated brine stream and/or substantially pure water streamproduced by the desalination system. That is to say, in certainembodiments, the pH adjustment apparatus can be located downstream ofthe desalination system.

In some embodiments, for example, a desalination system can befluidically connected to a VOM removal apparatus. In certain cases, thedesalination system is directly fluidically connected to the VOM removalapparatus. In some embodiments, the input stream received by thedesalination system comprises at least a portion of the VOM-diminishedstream produced by the VOM removal apparatus. That is to say, in certainembodiments, the desalination system is downstream of the VOM removalapparatus. In other embodiments, the input stream received by the VOMremoval comprises at least a portion of the concentrated brine streamand/or substantially pure water stream produced by the desalinationsystem. That is to say, in certain embodiments, the VOM removalapparatus can be located downstream of the desalination system.

Mixing Apparatus

In some embodiments, the water treatment system comprises an optionalmixing apparatus fluidically connected to the clean brine system and thedesalination system. A mixing apparatus generally refers to a deviceconfigured to mix a first fluid with a second fluid to form a fluidmixture (e.g., a substantially homogeneous fluid mixture). In someembodiments, the mixing apparatus is configured to receive at least aportion of a clean brine stream from a clean brine system describedherein. In some embodiments, the mixing apparatus is also configured toreceive at least a portion of a substantially pure water stream from adesalination system described herein. According to some embodiments, themixing apparatus is configured to mix at least a portion of the cleanbrine stream and at least a portion of the substantially pure waterstream to form a mixed water stream.

In some embodiments, the mixed water stream has a mixing ratio by massof the substantially pure water stream to the clean brine stream of atleast about 1:1, at least about 2:1, at least about 3:1, at least about4:1, at least about 5:1, at least about 10:1, at least about 20:1, atleast about 50:1, at least about 100:1, at least about 150:1, or atleast about 200:1. In some embodiments, the mixed water stream has amixing ratio by mass of the substantially pure water stream to the cleanbrine stream of about 1:1 or less, about 1:2 or less, about 1:3 or less,about 1:4 or less, about 1:5 or less, about 1:10 or less, about 1:20 orless, about 1:50 or less, about 1:100 or less, about 1:150 or less, orabout 1:200 or less. In certain cases, the mixed water stream has amixing ratio by mass of the substantially pure water stream to the cleanbrine stream in the range of about 1:200 to about 200:1, about 1:150 toabout 150:1, about 1:100 to about 100:1, about 1:50 to about 50:1, about1:20 to about 20:1, about 1:10 to about 10:1, about 1:5 to about 5:1, orabout 1:2 to about 2:1. In some embodiments, the mixed water stream hasa mixing ratio by mass of the substantially pure water stream to theclean brine stream in the range of about 1:1 to about 200:1, about 1:1to about 150:1, about 1:1 to about 100:1, about 1:1 to about 50:1, about1:1 to about 20:1, about 1:1 to about 10:1, about 1:1 to about 5:1,about 1:1 to about 4:1, about 1:1 to about 3:1, about 1:1 to about 2:1,about 2:1 to about 5:1, about 2:1 to about 4:1, about 2:1 to about 3:1,about 3:1 to about 10:1, about 3:1 to about 5:1, or about 5:1 to about10:1. The mixing ratio by mass may be calculated by dividing the mass ofthe amount of substantially pure water by the mass of the amount ofclean brine in a mixed water stream.

In some embodiments, the concentration of at least one salt (e.g., NaCl)in the mixed water stream is at least about 1,000 mg/L, at least about2,000 mg/L, at least about 5,000 mg/L, at least about 10,000 mg/L, atleast about 20,000 mg/L, at least about 50,000 mg/L, at least about100,000 mg/L, or at least about 150,000 mg/L. In some embodiments, theconcentration of at least one salt (e.g., NaCl) in the mixed waterstream is about 150,000 mg/L or less, about 100,000 mg/L or less, about50,000 mg/L or less, about 20,000 mg/L or less, about 10,000 mg/L orless, about 5,000 mg/L or less, about 2,000 mg/L or less, or about 1,000mg/L or less. In certain cases, the concentration of at least one saltin the mixed water stream is in the range of about 1,000 mg/L to about5,000 mg/L, about 1,000 mg/L to about 10,000 mg/L, about 1,000 mg/L toabout 15,000 mg/L, about 1,000 mg/L to about 20,000 mg/L, about 1,000mg/L to about 50,000 mg/L, about 1,000 mg/L to about 100,000 mg/L, about1,000 mg/L to about 150,000 mg/L, about 5,000 mg/L to about 10,000 mg/L,about 5,000 mg/L to about 15,000 mg/L, about 5,000 mg/L to about 20,000mg/L, about 5,000 mg/L to about 50,000 mg/L, about 5,000 mg/L to about100,000 mg/L, about 5,000 mg/L to about 150,000 mg/L, about 10,000 mg/Lto about 20,000 mg/L, about 10,000 mg/L to about 50,000 mg/L, about10,000 mg/L to about 100,000 mg/L, about 10,000 mg/L to about 150,000mg/L, about 20,000 mg/L to about 50,000 mg/L, about 20,000 mg/L to about100,000 mg/L, about 20,000 mg/L to about 150,000 mg/L, about 50,000 mg/Lto about 100,000 mg/L, or about 50,000 mg/L to about 150,000 mg/L.

In some embodiments, the total salt concentration in the mixed waterstream is at least about 10,000 mg/L, at least about 20,000 mg/L, atleast about 50,000 mg/L, at least about 100,000 mg/L, at least about110,000 mg/L, at least about 120,000 mg/L, at least about 150,000 mg/L,or at least about 200,000 mg/L. In some embodiments, the total saltconcentration in the mixed water stream is about 200,000 mg/L or less,about 150,000 mg/L or less, about 120,000 mg/L or less, about 100,000mg/L or less, about 100,000 mg/L or less, about 50,000 mg/L or less,about 20,000 mg/L or less, or about 10,000 mg/L or less. In certaincases, the total salt concentration in the mixed water stream is in therange of about 10,000 mg/L to about 20,000 mg/L, about 10,000 mg/L toabout 50,000 mg/L, about 10,000 mg/L to about 100,000 mg/L, about 10,000mg/L to about 110,000 mg/L, about 10,000 mg/L to about 120,000 mg/L,about 10,000 mg/L to about 150,000 mg/L, about 10,000 to about 200,000mg/L, about 20,000 mg/L to about 50,000 mg/L, about 20,000 mg/L to about100,000 mg/L, about 20,000 mg/L to about 150,000 mg/L, about 20,000 toabout 200,000 mg/L, about 50,000 mg/L to about 100,000 mg/L, about50,000 mg/L to about 150,000 mg/L, or about 50,000 mg/L to about 200,000mg/L.

In some embodiments, the mixed water stream comprises at least one salt(e.g., NaCl) in an amount of at least about 0.1 wt %, at least about 0.5wt %, at least about 1 wt %, at least about 2 wt %, at least about 5 wt%, at least about 10 wt %, or at least about 15 wt % (and/or, in certainembodiments, up to the solubility limit of the salt in the mixed waterstream). In some embodiments, the mixed water stream comprises at leastone salt in an amount in the range of about 0.1 wt % to about 1 wt %,about 0.1 wt % to about 2 wt %, about 0.1 wt % to about 5 wt %, about0.1 wt % to about 10 wt %, about 0.1 wt % to about 15 wt %, about 1 wt %to about 5 wt %, about 1 wt % to about 10 wt %, about 1 wt % to about 15wt %, about 2 wt % to about 5 wt %, about 2 wt % to about 10 wt %, about2 wt % to about 15 wt %, about 5 wt % to about 10 wt %, about 5 wt % toabout 15 wt %, or about 10 wt % to about 15 wt %.

In some embodiments, the mixed water stream has a total saltconcentration of at least about 1 wt %, at least about 5 wt %, at leastabout 10 wt %, at least about 15 wt %, at least about 20 wt %, at leastabout 25 wt %, at least about 26 wt %, at least about 27 wt %, at leastabout 28 wt %, at least about 29 wt %, or at least about 30 wt %. Insome embodiments, the mixed water stream has a total salt concentrationin the range of about 1 wt % to about 10 wt %, about 1 wt % to about 20wt %, about 1 wt % to about 25 wt %, about 1 wt % to about 26 wt %,about 1 wt % to about 27 wt %, about 1 wt % to about 28 wt %, about 1 wt% to about 29 wt %, about 1 wt % to about 30 wt %, about 10 wt % toabout 20 wt %, about 10 wt % to about 25 wt %, about 10 wt % to about 26wt %, about 10 wt % to about 27 wt %, about 10 wt % to about 28 wt %,about 10 wt % to about 29 wt %, about 10 wt % to about 30 wt %, about 20wt % to about 25 wt %, about 20 wt % to about 26 wt %, about 20 wt % toabout 27 wt %, about 20 wt % to about 28 wt %, about 20 wt % to about 29wt %, about 20 wt % to about 30 wt %, about 25 wt % to about 26 wt %,about 25 wt % to about 27 wt %, about 25 wt % to about 28 wt %, about 25wt % to about 29 wt %, or about 25 wt % to about 30 wt %.

The mixing apparatus may be any type of mixing apparatus known in theart. Non-limiting examples of suitable types of mixing apparatusesinclude static inline mixers, stirred tanks (e.g., tanks comprising anagitator), eductors, venturi mixers, plate-type mixers, and/or waferinline static mixers.

Water Treatment System

FIG. 7 is a schematic diagram of an exemplary water treatment system700, according to certain embodiments. The water treatment system shownin FIG. 7 includes a number of components that can be used to treat anaqueous stream containing at least one dissolved salt. According to FIG.7, water treatment system 700 comprises optional separation apparatus702 configured to receive aqueous input stream 704 comprising asuspended and/or emulsified immiscible phase. Optional separationapparatus 702 can be configured to remove at least a portion of thesuspended and/or emulsified immiscible phase to produceimmiscible-phase-diminished stream 706, which contains less of thesuspended and/or emulsified immiscible phase than stream 704. Separationapparatus 702 can also be configured to produce stream 705, which isenriched in the suspended and/or emulsified water-immiscible phaserelative to stream 704.

In FIG. 7, system 700 further comprises optional suspended solidsremoval apparatus 708, which can be configured to remove at least aportion of suspended solids from input stream 706 to produce asuspended-solids-diminished stream 710. Suspended solids removalapparatus 708 can be configured to produce stream 709, which is enrichedin the suspended solids relative to stream 706.

According to FIG. 7, system 700 further comprises optional ion-removalapparatus 712. Ion-removal apparatus 712 can be configured, according tocertain embodiments, to remove at least a portion of at least onescale-forming ion from stream 710 received by ion-removal apparatus 712.Ion-removal apparatus 712 can be configured to produce ion-diminishedstream 714, which contains less of the scale-forming ion relative toinput stream 710 received by ion-removal apparatus 712. Ion-removalapparatus 712 can also be configured to produce stream 713, which isenriched in at least one scale-forming ion relative to stream 710.

In FIG. 7, system 700 includes optional pH adjustment apparatus 716,which can be configured to receive aqueous input stream 714, which cancomprise scale-forming ions. pH adjustment apparatus 716 can beconfigured to increase or decrease the pH of aqueous input stream 714 toproduce a pH-adjusted stream 718. In certain cases, the pH of inputstream 714 may be reduced to inhibit the precipitation of scale-formingions. In some cases, the pH of input stream 714 can be increased ordecreased, for example, by adding chemicals via stream 717, according tosome embodiments. For example, an acidic composition can be added to thepH adjustment apparatus to reduce the pH of stream 714, in certainembodiments.

According to FIG. 7, system 700 further comprises optional VOM removalapparatus 720. VOM removal apparatus 720 can be configured to remove atleast a portion of VOM from input stream 718 received by VOM removalapparatus 720 to produce a VOM-diminished stream 722, which containsless of the VOM relative to input stream 718 received by VOM removalapparatus 720. VOM removal apparatus 720 can be configured to producestream 721, which is enriched in VOM relative to stream 718.

In FIG. 7, water treatment system 700 further comprises an optionaldesalination system 724, which is configured to remove water fromaqueous stream 722 received by desalination system 724 to produce aconcentrated brine stream 726 enriched in a dissolved salt relative toaqueous stream 722 received by desalination system 724.

Water treatment system 700 may also comprise optional precipitationapparatus 734. For example, in FIG. 7, precipitation apparatus 734 isfluidically connected to desalination system 724 and configured toreceive concentrated brine stream 726 from desalination system 724.Precipitation apparatus 734 can be configured such that at least aportion of the dissolved salt within concentrated brine stream 726precipitates within precipitation apparatus 734 to producewater-containing product stream 736, which contains less dissolved saltthan concentrated brine stream 726, and solid salt stream 738.

According to FIG. 7, water treatment system 700 can comprise an optionaldisinfection unit 730. Disinfection unit 730 can be configured toreceive at least a portion of water-containing stream 725 fromdesalination system 724. In some embodiments, disinfection unit 730 canbe configured to receive disinfectant stream 731, which can contain, forexample, chlorine. Disinfection unit 730 can be configured to producedisinfected water-containing stream 732.

FIG. 8 is a schematic illustration of an exemplary water treatmentsystem 800, according to certain embodiments. In FIG. 8, aqueous inputstream 804 is transported to optional tank 806. In some embodiments,chemicals are added to optional tank 806 via stream 808. The chemicalscan be selected to aid in a downstream apparatus, according to certainembodiments. For example, in some embodiments, a skimmer (which can bepart of a dissolved gas flotation apparatus, for example) can bepositioned downstream of tank 806, and the chemicals added to tank 806are selected to aid in operation of the skimmer (e.g., in a dissolvedgas flotation process). Aqueous stream 810 can be transported out oftank 806. Aqueous stream 810 can be transported to skimmer 814. In someembodiments, skimmer 814 can be configured to remove at least a portionof a suspended and/or emulsified water-immiscible phase within stream810 to produce an immiscible-phase-diminished stream 822 (and, in someembodiments, immiscible-phase-diminished stream 818). Thewater-immiscible phase from skimmer 814 can be transported, for example,to a recovery tank 826 via stream 820. In some embodiments, skimmer 814is part of a dissolved gas flotation apparatus. In some suchembodiments, compressed gas (e.g., air) can be added, via stream 812, toa tank containing the treated water, which can aid in the transport ofimmiscible material to the top of the tank. Gas can subsequently betransported out of the tank via stream 816.

In some embodiments, ion-removal apparatus 828 can be configured toreceive at least a portion of immiscible-phase-diminished stream 822. Insome embodiments, ion-removal apparatus 828 is configured to remove atleast a portion of scale-forming ions within stream 822 to produce anion-diminished stream 832. In some such embodiments, ion-removalapparatus 828 produces ion-diminished stream 832 using a chemicalreagent. For example, in FIG. 8, chemical reagent can be transported toion-removal apparatus 828 via stream 830. The chemical reagent can be,for example, soda ash, caustic soda, and the like.

In certain embodiments, a portion of the immiscible-phase-diminishedstream produced by skimmer 814 can bypass ion-removal apparatus 828. Forexample, in FIG. 8, at portion of the immiscible-phase-diminished streamfrom skimmer 814 bypasses ion-removal apparatus 828 via stream 818. Thecontents of bypass stream 818 may be merged with the contents of stream832 downstream of ion-removal apparatus 828.

In some embodiments, a filter is configured to receive at least aportion of the immiscible-phase-diminished stream and/or at least aportion of the ion-diminished stream. For example, in FIG. 8, filter 834is configured to received ion-diminished stream 832 and/orimmiscible-phase-diminished stream 818. In certain embodiments, filter834 is configured to remove at least a portion of suspended solids fromthe immiscible-phase-diminished stream portion and/or the ion-diminishedstream portion received by the filter to produce asuspended-solids-diminished stream. For example, in FIG. 8, filter 834is configured to remove at least a portion of suspended solids fromstream 832 to produce suspended-solids-diminished stream 838. Inaddition, in FIG. 8, filter 834 is configured to producesolids-containing stream 836.

In certain embodiments, a pH adjustment step can be included in theprocess. For example, in FIG. 8, optional tank 840 can be configured toreceive suspended-solids-diminished stream 838 and to output pH-adjusted(e.g., pH-reduced) stream 844. Tank 840 can be configured, in someembodiments, to receive an acid and/or a base via stream 842. In somesuch embodiments, an acid and/or base may be added to tank 840 until thepH of the contents of tank 840 reaches a desired level. According tocertain embodiments, the contents of tank 840 may be output via stream844, once the pH has reached a desired level. In certain embodiments,tank 840 is a reactor, such as a continuous flow stirred tank reactor.In some such embodiments, acid and/or base can be constantly fed at arate such that the reactor effluent reaches a desired pH level.

In some embodiments, optional filter 846 can be included in the system.Filter 846 can be used to remove one or more solid materials frompH-adjusted stream 844 to produce filtered stream 848.

According to certain embodiments, a carbon bed is configured to receiveat least a portion of the filtered stream. For example, in FIG. 8,carbon bed 850 is configured to receive filtered stream 848 produced byfilter 846. Carbon bed 850 can be configured to remove at least aportion of VOM from the filtered stream portion received by the carbonbed to produce a VOM-diminished stream. For example, in FIG. 8, carbonbed 850 is configured to produce VOM-diminished stream 852.

In some embodiments, a desalination system is configured to receive atleast a portion of the VOM-diminished stream and to remove at least aportion of water from the VOM-diminished stream received by thedesalination system. For example, in FIG. 8 desalination system 854 isconfigured to receive VOM-diminished stream 852. In addition,desalination system 854 is configured to produce concentrated brinestream 856, which is enriched in at least one dissolved salt (e.g.,dissolved monovalent salt) relative to VOM-diminished stream 852. Insome embodiments, the desalination system can also produce awater-containing stream that contains a lower concentration of thedissolved salt (e.g., dissolved monovalent salt) than the stream fed tothe desalination system. For example, in FIG. 8, desalination system 854can be configured to produce water-containing stream 858, which containsless of a dissolved salt (e.g., less of a dissolved monovalent salt)than stream 852 fed to desalination system 854.

In certain embodiments, the order of the desalination system and thecarbon bed can be switched, relative to the order shown in FIG. 8. Forexample, in some embodiments, the desalination system is configured toreceive at least a portion of the suspended-solids-diminished stream,and to remove at least a portion of water from thesuspended-solids-diminished stream portion received by the desalinationsystem to produce a concentrated brine stream enriched in a dissolvedsalt relative to the suspended-solids-diminished stream portion receivedby the desalination system. The desalination system can also beconfigured to produce a water-containing stream containing less of thedissolved salt than the suspended-solids-diminished stream. In some suchembodiments, the carbon bed can be configured to receive at least aportion of the water-containing stream produced by the desalinationsystem, and to remove at least a portion of VOM from thewater-containing stream portion received by the carbon bed to produce aVOM-diminished stream.

FIG. 9 is a schematic illustration of another exemplary water treatmentsystem 900, according to certain embodiments. In FIG. 9, aqueous inputstream 904 is transported to optional tank 906. In some embodiments,chemicals are added to optional tank 906 via stream 908. The chemicalscan be selected to aid in a downstream apparatus, according to certainembodiments. For example, in some embodiments, a skimmer (which can bepart of a dissolved gas flotation apparatus, for example) can bepositioned downstream of tank 906, and the chemicals added to tank 906are selected to aid in operation of the skimmer (e.g., in a dissolvedgas flotation process). Aqueous stream 910 can be transported out oftank 906. Aqueous stream 910 can be transported to skimmer 914. In someembodiments, skimmer 914 can be configured to remove at least a portionof suspended and/or emulsified water-immiscible phase within stream 910to produce an immiscible-phase-diminished stream 922 (and, in someembodiments, immiscible-phase-diminished stream 918). Thewater-immiscible phase from skimmer 914 can be transported, for example,to a recovery tank 926 via stream 920. In some embodiments, skimmer 914is part of a dissolved gas flotation apparatus. In some suchembodiments, compressed gas (e.g., air) can be added, via stream 912, toa tank containing the treated water, which can aid in the transport ofimmiscible material to the top of the tank. Gas can subsequently betransported out of the tank via stream 916.

In some embodiments, electrocoagulation apparatus 928 can be configuredto receive at least a portion of water-immiscible phase-diminishedstream 922. Electrocoagulation apparatus 928 can be configured to removeat least a portion of scale-forming ions within stream 922 to produce anion-diminished stream 932.

In certain embodiments, a portion of water-immiscible phase-diminishedstream produced by skimmer 914 can bypass electrocoagulation apparatus928. For example, in FIG. 9, a portion of the immisciblephase-diminished product from skimmer 914 bypasses electrocoagulationapparatus 928 via stream 918. The contents of bypass stream 918 may bemerged with the contents of stream 932 downstream of electrocoagulationapparatus 928.

Filter 934 can be configured to receive ion-diminished stream 932 and/orimmiscible-phase-diminished stream 918. Filter 934 can be configured toremove at least a portion of suspended solids from stream 932 to producesuspended-solids-diminished stream 938. In addition, filter 934 can beconfigured to produce solids-containing stream 936.

In certain embodiments, a pH adjustment step can be included in theprocess. For example, in FIG. 9, optional tank 940 can be configured toreceive suspended-solids-diminished stream 938 and to producepH-adjusted stream 944. Optional tank 940 can be configured, in someembodiments, to receive an acid and/or a base via stream 942. In somesuch embodiments, an acid and/or base may be added to tank 940 until thepH of the contents of tank 940 reaches a desired level. In certainembodiments, tank 940 is a reactor, such as a continuous flow stirredtank reactor. In some such embodiments, an acid and/or base can beconstantly fed at a rate such that the reactor effluent reaches adesired pH level. According to certain embodiments, the contents of tank940 may be output via stream 944, once the pH has reached a desiredlevel.

In some embodiments, optional filter 946 can be included in the system.Filter 946 can be used to remove one or more solid materials frompH-adjusted stream 944 to produce filtered stream 948.

Carbon bed 950 can be configured to receive filtered stream 948 producedby filter 946. Carbon bed 950 can be configured to remove at least aportion of VOM from the filtered stream portion received by the carbonbed to produce a VOM-diminished stream 952.

Desalination system 954 can be configured to receive VOM-diminishedstream 952. Desalination system 954 can be configured to produceconcentrated brine stream 956, which is enriched in at least onedissolved salt (e.g., dissolved monovalent salt) relative toVOM-diminished stream 952. Desalination system 954 can also beconfigured to produce water-containing stream 958, which contains lessof a dissolved salt (e.g., dissolved monovalent salt) than stream 952fed to desalination system 954.

In certain embodiments, the order of the desalination system and thecarbon bed can be switched, relative to the order shown in FIG. 9. Forexample, in some embodiments, the desalination system is configured toreceive at least a portion of the suspended-solids-diminished stream,and to remove at least a portion of water from thesuspended-solids-diminished stream portion received by the desalinationsystem to produce a concentrated brine stream enriched in a dissolvedsalt (e.g., dissolved monovalent salt) relative to thesuspended-solids-diminished stream portion received by the desalinationsystem. The desalination system can also be configured to produce awater-containing stream containing less of the dissolved salt (e.g.,dissolved monovalent salt) than the suspended-solids-diminished stream.In some such embodiments, the carbon bed can be configured to receive atleast a portion of the water-containing stream produced by thedesalination system, and to remove at least a portion of VOM from thewater-containing stream portion received by the carbon bed to produce aVOM-diminished stream.

FIG. 10 is a schematic illustration of another exemplary water treatmentsystem 1000, according to certain embodiments. In FIG. 10, aqueous inputstream 1004 is transported to optional tank 1006. In some embodiments,chemicals are added to optional tank 1006 via stream 1008. The chemicalscan be selected to aid in a downstream apparatus, according to certainembodiments. For example, in some embodiments, a skimmer (which can bepart of a dissolved gas flotation apparatus, for example) can bepositioned downstream of tank 1006, and the chemicals added to tank 1006are selected to aid in operation of the skimmer (e.g., in a dissolvedgas flotation process). Aqueous stream 1010 can be transported out oftank 1006. Aqueous stream 1010 can be transported to skimmer 1014. Insome embodiments, skimmer 1014 can be configured to remove at least aportion of suspended and/or emulsified water-immiscible phase withinstream 1010 to produce an immiscible-phase-diminished stream 1022 (and,in some embodiments, immiscible-phase-diminished stream 1018). Thewater-immiscible phase from skimmer 1014 can be transported, forexample, to a recovery tank 1026 via stream 1020. In some embodiments,skimmer 1014 is part of a dissolved gas flotation apparatus. In somesuch embodiments, compressed gas (e.g., air) can be added, via stream1012, to a tank containing the treated water, which can aid in thetransport of immiscible material to the top of the tank. Gas cansubsequently be transported out of the tank via stream 1016.

In certain embodiments, a portion of water-immiscible phase-diminishedstream produced by skimmer 1014 can be transported to filter 1019, forexample, via stream 1018. Filter 1019 can be configured to remove atleast a portion of suspended solids from immiscible-phase-diminishedstream portion 1018 received by filter 1019 to produce asuspended-solids-diminished stream 1024. Filter 1019 can also beconfigured to produce a solids-containing stream 1036.

In some embodiments, a portion of the water-immiscible phase-diminishedstream produced by skimmer 1014 can bypass filter 1019. For example, inFIG. 10, a portion 1022 of the immiscible phase-diminished product fromskimmer 1014 bypasses filter 1019 via stream 1022. The contents ofbypass stream 1022 may be merged with the contents of stream 1024downstream of filter 1019 and skimmer 1014 to produce stream 1023.

In certain embodiments, an optional pH adjustment step can be includedin the process. For example, in FIG. 10, optional tank 1040 can beconfigured to receive suspended-solids-diminished stream 1023 and toproduce pH-adjusted stream 1044. Optional tank 1040 can be configured,in some embodiments, to receive an acid and/or a base via stream 1042.In some such embodiments, an acid and/or base may be added to tank 1040until the pH of the contents of tank 1040 reaches a desired level. Incertain embodiments, tank 1040 is a reactor, such as a continuous flowstirred tank reactor. In some such embodiments, an acid and/or base canbe constantly fed at a rate such that the reactor effluent reaches adesired pH level. According to certain embodiments, the contents of tank1040 may be output via stream 1044, once the pH has reached a desiredlevel.

In some embodiments, media filter 1034 can be configured to receivepH-adjusted stream 1044 (and/or suspended-solids-diminished stream1023). Media filter 1034 can be configured to remove at least a portionof suspended solids from stream 1044 to produce stream 1038.

In some embodiments, a carbon bed can be included in the system. Forexample, referring to FIG. 10, carbon bed 1050 can be configured toreceive stream 1038, which contains at least a portion of the streamproduced by filter 1034. Carbon bed 1050 can be configured to remove atleast a portion of VOM from the stream received by the carbon bed toproduce a VOM-diminished stream 1052.

In some embodiments, a resin bed can be included in the system. Forexample, in FIG. 10, resin bed 1060 can be configured to receive atleast a portion of VOM-diminished stream 1052. Resin bed 1060 can beconfigured to remove at least a portion of at least one scale-formingion from VOM-diminished stream portion 1052 received by resin bed 1060to produce ion-diminished stream 1062 containing less of thescale-forming ion relative to input stream 1052 received by resin bed1060.

In some embodiments, desalination system 1054 can be configured toreceive ion-diminished stream 1062. Desalination system 1054 can beconfigured to produce concentrated brine stream 1056, which is enrichedin at least one dissolved salt (e.g., monovalent salt) relative toion-diminished stream 1062. Desalination system 1054 can also beconfigured to produce water-containing stream 1058, which contains lessof a dissolved salt (e.g., a dissolved monovalent salt) than stream 1062fed to desalination system 1054.

In certain embodiments, the order of the desalination system and thecarbon bed can be switched, relative to the order shown in FIG. 10. Forexample, in some embodiments, the desalination system is configured toreceive at least a portion of the suspended-solids-diminished stream,and to remove at least a portion of water from thesuspended-solids-diminished stream portion received by the desalinationsystem to produce a concentrated brine stream enriched in a dissolvedsalt relative to the suspended-solids-diminished stream portion receivedby the desalination system. The desalination system can also beconfigured to produce a water-containing stream containing less of thedissolved salt than the suspended-solids-diminished stream. In some suchembodiments, the carbon bed can be configured to receive at least aportion of the water-containing stream produced by the desalinationsystem, and to remove at least a portion of VOM from thewater-containing stream portion received by the carbon bed to produce aVOM-diminished stream.

Certain of the systems described herein can be configured to desalinatesaline solutions entering at relatively high flow rates, andaccordingly, can be configured to produce relative pure water streams atrelatively high flow rates. For example, in some embodiments, thesystems and methods described herein may be operated to receive anaqueous saline feed stream (e.g., streams 104 in FIG. 1, 804 in FIG. 8,904 in FIG. 9, and/or 1004 in FIG. 10) at a flow rate of at least about1 gallon/minute, at least about 10 gallons/minute, at least about 100gallons/minute, or at least about 1000 gallons/minute (and/or, incertain embodiments, up to about 10,000 gallons/minute, or more).

Example 1

In this example, a water treatment system comprising a clean brinesystem, a desalination system, and a mixing apparatus is described.

As shown in FIG. 1, water treatment system 100 comprises clean brinesystem 102, humidification-dehumidification desalination system 110, andmixing apparatus 116. In operation, saline water input stream 104 (e.g.,a produced water stream) having a dissolved NaCl concentration of140,000 ppm enters clean brine system 102 at a flow rate of 12,000barrels/day. In clean brine system 102, a first clean brine stream 106having a dissolved NaCl concentration of 140,000 ppm is produced at arate of 4,000 barrels/day. A second clean brine stream 108, which has alower concentration of at least one scale-forming ion than first cleanbrine stream 106, is produced at a rate of about 8,000 barrels/day andis fed into desalination system 110. In desalination system 110, atleast a portion of water is removed from clean brine stream 108 toproduce a substantially pure water stream 112 and a concentrated brinestream 114. Substantially pure water stream 112, which has a dissolvedNaCl concentration of less than about 500 ppm, is produced at a rate ofabout 4,000 barrels/day. Concentrated brine stream 114, which has adissolved NaCl concentration of 260,000 ppm, is produced at a rate ofabout 4,000 barrels/day. Approximately 1,000 barrels/day of first cleanbrine stream 106 are mixed with about 3,000 barrels/day of substantiallypure water stream 112 in mixing apparatus 116 to produce about 4,000barrels/day of mixed water product 118 having a dissolved NaClconcentration of about 35,000 ppm.

Example 2

In this example, a water treatment system as in Example 1 was used totreat produced water from Midland, Tex. and obtain clean brine fordirect use, clean brine for desalination, substantially pure water, andconcentrated brine. Table 1 lists the concentrations of variousconstituents of the different water streams. Concentrations for a mixedwater product comprising 3:1 pure water to clean brine for direct usewere estimated based on the concentrations obtained for substantiallypure water and clean brine for direct use. In Table 1, ND stands for“not detected.” To calculate hardness, the molar concentration ofvarious divalent ions was measured, then mg/L concentration wascalculated as if each of those ions were a calcium ion.

FIG. 11 shows a schematic diagram of the clean brine system used. Asshown in FIG. 11, clean brine system 1100 comprised buffer tanks 1102Aand 1102B, reaction tanks 1104A, 1104B, and 1104C, clarifier 1106,polishing filter 1108, resin beds 1110, pH adjustment tank 1112, holdingtank 1114, and filter 1116. In operation, aqueous feed stream 1118(e.g., produced water) was pumped to buffer tanks 1102A and 1102B, eachof which had a height of about 15 feet and a volume of about 3,000gallons. The presence of buffer tanks 1102A and 1102B assisted inmitigating any unsteadiness in the flow rate of aqueous feed stream1118. In buffer tanks 1102A and 1102B, a small amount of floating oilwas removed by a belt oil skimmer. The residence time of aqueous feedstream 1118 in buffer tanks 1102A and 1102B was about 10 minutes. Frombuffer tanks 1102A and 1102B, a stream 1120 was directed to firstreaction tank 1104A. In first reaction tank 1104A, soda ash and acoagulant comprising barium chloride were added to stream 1120 toproduce stream 1122. The coagulant comprising barium chloride was addedto precipitate sulfate ions present in the stream as barium sulfate.Stream 1122 was then directed to flow to second reaction tank 1104B. Insecond reaction tank 1104B, caustic soda was added to stream 1122 toproduce stream 1124. Stream 1124 was then directed to flow to thirdreaction tank 1104C, where a polymer flocculent was added to stream 1124to produce stream 1126. Stream 1126 was directed to flow to clarifier1106. Clarifier 1106 was a lamella plate clarifier configured to removesolids by settling. An amount of oil was also removed (e.g., throughentrapment of oil droplets by solid precipitates, through adhesion ofoil droplets with solid precipitates as a result of collisions). As aresult, clarifier 1106 produced a solid-diminished stream 1128 and asolid-containing stream 1130.

Solid-diminished stream 1128 was directed to flow to polishing filter1108 to further remove solids from stream 1128 and produce filteredstream 1134. In this embodiment, the polishing filter was a multi-mediafilter. When too many particles collected in filter 1108, flow throughfilter 1108 slowed, and filter 1108 was automatically cleaned bybackwashing. In the backwashing process, clean brine and hydrochloricacid were flushed through filter 1108 in opposite directions, fluidizingand suspending the media and freeing collected particles. Backwash wasreintroduced into the aqueous stream upstream of filter 1108.

Filtered stream 1134 was then directed to flow to ion-exchange resinbeds 1110 to form stream 1136. Stream 1136 was then flowed to pHadjustment tank 1112. In pH adjustment tank 1112, hydrochloric acid wasadded to stream 1136 to produce pH-adjusted stream 1138, which had a pHaround 7. During the precipitation step in reaction tanks 1104A-C, thepH was raised to 10 or 11 to decrease the solubility of calciumcarbonate and magnesium hydroxide.

In one case, at least a portion of pH-adjusted stream 1138 wasdischarged from system 1100 as a clean brine stream for reuse. Inanother case, at least a portion of pH-adjusted stream 1138 wassubsequently flowed to a humidification-dehumidification desalinationsystem to produce a substantially pure water stream and a concentratedbrine stream. Significantly less (or substantially no) soda ash wasadded to the produced water to produce the clean brine stream for reusecompared to the amount of soda ash added to produce the clean brinestream for desalination. The concentrations of various constituents inthe clean brine for reuse, clean brine for desalination, substantiallypure water, and concentrated brine are shown in Table 1.

Solid-containing stream 1130 produced by clarifier 1106 was initiallydirected to flow from clarifier 1106 to holding tank 1114, and then fromholding tank 1114 to filter 1116. Filter 1116 was a rotary vacuum drumfilter comprising a round drum covered in a filter cloth. Diatomaceousearth was applied to the filter cloth as a precoat to aid filtration.The drum, covered in diatomaceous earth, was partially submerged insolid-containing stream 1130 and rotated slowly. A vacuum was applied tothe interior of the drum, causing liquid to be drawn through the drumand solid material to form a cake around the outside of the drum. Whatthe cake was sufficiently large, it was removed by scraping with astationary blade. This process resulted in substantially solid material1132.

TABLE 1 Clean Clean Brine Produced Brine for for Pure Concentrated MixedConstituent Water Reuse Desalination Water Brine Water Barium 3.78 mg/L16.1 mg/L 6.55 mg/L 0.017 mg/L 1.51 mg/L 4.04 mg/L Bromide 1390 mg/L1360 mg/L 1350 mg/L 2.78 mg/L 3960 mg/L 342 mg/L Calcium 2350 mg/L 1720mg/L 121 mg/L 1.85 mg/L 345 mg/L 431 mg/L Chloride 70100 mg/L 76400 mg/L65800 mg/L 130 mg/L 159000 mg/L 19200 mg/L Sulfate 282 mg/L 222 mg/L 255mg/L ND 710 mg/L 55.5 mg/L Magnesium 375 mg/L 359 mg/L ND ND 61.6 mg/L89.8 mg/L Oil & Grease 22.5 mg/L ND ND ND ND ND Sodium 41700 mg/L 43100mg/L 46000 mg/L 89.3 mg/L 96400 mg/L 10800 mg/L Strontium 712 mg/L 586mg/L 101 mg/L 0.379 mg/L 277 mg/L 147 mg/L Benzene 1960 μg/L 1560 μg/L88.4 μg/L ND ND 390 μg/L Toluene 1230 μg/L 929 μg/L 50.8 μg/L ND ND 232μg/L pH 6.55 7.15 7.75 8.18 5.55 8.03 Hardness 7420 mg/L 5780 mg/L 303mg/L 4.61 mg/L 1120 mg/L 1450 mg/L expressed as mg/L Ca²⁺ Total 125000mg/L 121000 mg/L 113000 mg/L 234 mg/L 320000 mg/L 30400 mg/L DissolvedSolids Total 535 mg/L 410 mg/L 246 mg/L ND 636 mg/L 102.5 mg/L SuspendedSolids

While several embodiments of the present invention have been describedand illustrated herein, those of ordinary skill in the art will readilyenvision a variety of other means and/or structures for performing thefunctions and/or obtaining the results and/or one or more of theadvantages described herein, and each of such variations and/ormodifications is deemed to be within the scope of the present invention.More generally, those skilled in the art will readily appreciate thatall parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the teachings of thepresent invention is/are used. Those skilled in the art will recognize,or be able to ascertain using no more than routine experimentation, manyequivalents to the specific embodiments of the invention describedherein. It is, therefore, to be understood that the foregoingembodiments are presented by way of example only and that, within thescope of the appended claims and equivalents thereto, the invention maybe practiced otherwise than as specifically described and claimed. Thepresent invention is directed to each individual feature, system,article, material, and/or method described herein. In addition, anycombination of two or more such features, systems, articles, materials,and/or methods, if such features, systems, articles, materials, and/ormethods are not mutually inconsistent, is included within the scope ofthe present invention.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Other elements may optionallybe present other than the elements specifically identified by the“and/or” clause, whether related or unrelated to those elementsspecifically identified unless clearly indicated to the contrary. Thus,as a non-limiting example, a reference to “A and/or B,” when used inconjunction with open-ended language such as “comprising” can refer, inone embodiment, to A without B (optionally including elements other thanB); in another embodiment, to B without A (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of.” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” and the like are to be understoodto be open-ended, i.e., to mean including but not limited to. Only thetransitional phrases “consisting of” and “consisting essentially of”shall be closed or semi-closed transitional phrases, respectively, asset forth in the United States Patent Office Manual of Patent ExaminingProcedures, Section 2111.03.

In cases where the present specification and a document incorporated byreference, attached as an appendix, and/or referred to herein includeconflicting disclosure, and/or inconsistent use of terminology, and/orthe incorporated/appended/referenced documents use or define termsdifferently than they are used or defined in the present specification,the present specification shall control.

What is claimed is:
 1. A method for treating water, comprising:supplying a first portion of a saline water input stream having a firstconcentration of a scale-forming ion to an ion-removal apparatus;removing, within the ion-removal apparatus in a first ion-removal step,at least a portion of the scale-forming ion from the first portion ofthe saline water input stream by adding at least one ion-removalcomposition to the ion-removal apparatus to induce precipitation of theportion of the scale-forming ion within the first portion of the salinewater input stream and produce a first ion-diminished stream having asecond concentration of the scale-forming ion, wherein the secondconcentration is lower than the first concentration; collecting aproduct stream comprising at least a portion of the first ion-diminishedstream; after removing, within the ion-removal apparatus in the firstion-removal step, at least a portion of the scale-forming ion from thefirst portion of the saline water input stream to produce the firstion-diminished stream, removing, within the ion-removal apparatus in asecond ion-removal step, at least a portion of the scale-forming ionfrom a second portion of the saline water input stream by adding atleast one ion-removal composition to the ion-removal apparatus to induceprecipitation of the portion of the scale-forming ion within the secondportion of the saline water input stream and produce a secondion-diminished stream having a third concentration of the scale-formingion, wherein the third concentration is lower than the secondconcentration; and feeding the second ion-diminished stream to adesalination system to produce a substantially pure water stream havinga lower concentration of a dissolved salt than the second ion-diminishedstream and a concentrated brine stream having a higher concentration ofthe dissolved salt than the second ion-diminished stream, wherein the atleast one ion-removal composition that is added to the ion-removalapparatus in the second ion-removal step comprises at least one chemicalthat: induces precipitation of scale-forming ions in the secondion-removal step, and was either not added to the ion-removal apparatusduring the first ion-removal step or was added to the ion-removalapparatus during the first ion-removal step in an amount that isdifferent from an amount of the chemical added during the secondion-removal step.
 2. The method according to claim 1, further comprisingmixing at least a portion of the first ion-diminished stream and atleast a portion of the substantially pure water stream to produce amixed water stream.
 3. The method according to claim 2, wherein themixing ratio by mass of the substantially pure water stream to the firstion-diminished stream is in the range of about 2:1 to about 4:1.
 4. Themethod according to claim 2, wherein the product stream is a firstproduct stream, and further comprising collecting a second productstream comprising at least a portion of the substantially pure waterstream, collecting a third product stream comprising at least a portionof the concentrated brine stream, and/or collecting a fourth productstream comprising at least a portion of the mixed water stream.
 5. Themethod according to claim 1, wherein at least about 5% of thescale-forming ion is removed from the saline water input stream withinthe ion-removal apparatus to produce the first ion-diminished stream. 6.The method according to claim 1, wherein the first ion-diminished streamcontains the scale-forming ion in an amount of about 5000 mg/L or less.7. The method according to claim 1, wherein the second ion-diminishedstream contains the scale-forming ion in an amount of about 750 mg/L orless.
 8. The method according to claim 1, further comprising removing,within a separation apparatus fluidically connected to the ion-removalapparatus, at least a portion of a suspended and/or emulsifiedimmiscible phase from the saline water input stream, the firstion-diminished stream, and/or the second ion-diminished stream to format least one immiscible-phase-diminished stream.
 9. The method accordingto claim 8, wherein the separation apparatus comprises an induced airflotation (IAF) separator.
 10. The method according to claim 8, furthercomprising removing, within a suspended solids removal apparatusfluidically connected to the ion-removal apparatus, at least a portionof suspended solids from the saline water input stream, the firstion-diminished stream, the second ion-diminished stream, and/or the atleast one immiscible-phase-diminished stream to form at least onesuspended-solids-diminished stream.
 11. The method according to claim10, further comprising increasing or decreasing the pH of the firstion-diminished stream, the second ion-diminished stream, the at leastone immiscible-phase-diminished stream, and/or the at least onesuspended-solids-diminished stream to form at least one pH-adjustedstream.
 12. The method according to claim 11, further comprisingremoving, within a volatile organic material (VOM) removal apparatusfluidically connected to the ion-removal apparatus, at least a portionof VOM from the saline water input stream, the first ion-diminishedstream, the second ion-diminished stream, the at least oneimmiscible-phase-diminished stream, the at least onesuspended-solids-diminished stream, and/or the at least one pH-adjustedstream to form at least one VOM-diminished stream.
 13. The methodaccording to claim 1, further comprising precipitating at least aportion of the salt from the concentrated brine stream.
 14. The methodaccording to claim 1, wherein the desalination system is ahumidification-dehumidification (HDH) desalination system.
 15. Themethod according to claim 14, wherein the HDH system comprises a bubblecolumn humidifier and/or a bubble column dehumidifier.
 16. The methodaccording to claim 1, wherein the dissolved salt is sodium chloride(NaCl).
 17. The method of claim 1, wherein the at least one ion-removalcomposition that is added to the ion-removal apparatus in the secondion-removal step comprises at least one chemical that: inducesprecipitation of scale-forming ions in the second ion-removal step, andwas not added to the ion-removal apparatus during the first ion-removalstep.
 18. The method of claim 1, wherein the at least one ion-removalcomposition that is added to the ion-removal apparatus in the secondion-removal step comprises at least one chemical that: inducesprecipitation of scale-forming ions in the second ion-removal step, andwas added to the ion-removal apparatus during the first ion-removal stepin an amount that is different from an amount of the chemical addedduring the second ion-removal step.
 19. The method of claim 1, whereinthe ion-removal apparatus is part of a water treatment system, andfurther comprising discharging the collected product stream from thewater treatment system to be used in an oil and gas extractionoperation.